Planning a home extension, where to start?
Discussion
DickyC said:
smokey mow said:
I wasn’t questioning you. Just pointing out to the OP that it won’t be exempt if that’s what they were hoping for so as to save some money.
The basic 'recipe' with extensions is that you're only allowed 25% of the floor area of the extension, plus the area of any existing doors and windows being enclosed by it, as glazed area for the extension. You can go over this, but you have to provide calculations to show that you are compensating for the additional heat loss through the glazing by reducing heat loss elsewhere.
The problem is that the 'base' U-values that you have to achieve anyway have now been improved to a point where improving them further, sufficiently to make a difference in the trade-off calculations, is becoming very difficult (not to mention expensive, if you have to resort to triple glazing).
You may be lucky and have a property where the area of existing doors and windows you're enclosing is large, but beyond that there are no magic-wand solutions for compliance... you're back to the old trick of building it as a conservatory (min. 75% glazed roof, 50% glazed walls, max. 30m2 floor area, thermally separated from the main dwelling), then remove the thermal separation after Building Regulations sign-off and live with the crippling fuel bills and a space that is too cold in winter and too warm in summer.
Edited by Equus on Thursday 18th January 09:52
DickyC said:
Planning a 4.5 x 5.5 single storey extension we hired an architect, he produced the drawings and his engineer mate checked the calcs. Complications included access and us wanting a small utility room and the adjacent aged kitchen extension's roof to line up. Then we tried to find a builder. Very little interest. A few dubious lads came round and pulled numbers out of the air. Then we found a reputable builder prepared to quote. Lovely, buildery sort of bloke, came round, measured up and a few days later a very detailed quote arrived. £80,000 + VAT for the groundwork, footings, shell and roof. That was it. His suggested contingencies for windows, doors, heating, electrics, rough screed and plastering brought it up to £160,000 without top screed, flooring, skirting or decorating.
Abandoning the architect's work, we went with a local firm of conservatory builders who built a 4.5 x 4.5 orangery, all in except the floor and decorating, for £60,000. We compromised on the utility room and old kitchen roof. Jeez, they did work hard and did a lovely job.
It might be worth considering. Anyone thinking about a single storey extension should give it some thought as an alternative to architect and builder.
I'm looking at doing the same thing, do you mind posting their details?Abandoning the architect's work, we went with a local firm of conservatory builders who built a 4.5 x 4.5 orangery, all in except the floor and decorating, for £60,000. We compromised on the utility room and old kitchen roof. Jeez, they did work hard and did a lovely job.
It might be worth considering. Anyone thinking about a single storey extension should give it some thought as an alternative to architect and builder.
I've had some quotes from architects, most of them were pie in the sky figures. There was one reasonable guy who quoted £2.5k, came round and measured everything, sent me some initial drawings and then disappeared off the face of the earth without charging me anything.
Shaoxter said:
I'm looking at doing the same thing, do you mind posting their details?
I've had some quotes from architects, most of them were pie in the sky figures. There was one reasonable guy who quoted £2.5k, came round and measured everything, sent me some initial drawings and then disappeared off the face of the earth without charging me anything.
oakleygreen-conservatories.co.ukI've had some quotes from architects, most of them were pie in the sky figures. There was one reasonable guy who quoted £2.5k, came round and measured everything, sent me some initial drawings and then disappeared off the face of the earth without charging me anything.
Oakley Green Conservatories
Thatcham, Berks
I think they have a branch near Bath or Bristol as well but they cover the whole of southern England.
Have you read Equus's post above? I may only just have made it in time.
Get your plans and print off a load - sketch your ideas, work with your wife/partner to go through what would you use it for, which direction does it face, do you want to re-model the kitchen into an open plan space, etc etc.....
Almost go wild with your ideas
Then get a professional to assess what you'd like to do and ask for quotes/opinions on the practicality and cost of what you want to do.
We finished a significant renovation about this time last year - on paper it looks like it's not something that would add value, but in reality the whole remodelling work has vastly improved how we use the place.
I'm thinking if you want to knock down the conservatory, that actually means you don't use it. So the key question is what would you do with the new space?
If you don't want to do the sketches - find someone you can work with as mentioned in another post and go through your ideas - if they're any good they will ask the questions above before making some conceptual suggestions.
As this was our second renovation, we almost designed the lot and then got an architect to make sure we weren't being completely ridiculous.
Almost go wild with your ideas
Then get a professional to assess what you'd like to do and ask for quotes/opinions on the practicality and cost of what you want to do.
We finished a significant renovation about this time last year - on paper it looks like it's not something that would add value, but in reality the whole remodelling work has vastly improved how we use the place.
I'm thinking if you want to knock down the conservatory, that actually means you don't use it. So the key question is what would you do with the new space?
If you don't want to do the sketches - find someone you can work with as mentioned in another post and go through your ideas - if they're any good they will ask the questions above before making some conceptual suggestions.
As this was our second renovation, we almost designed the lot and then got an architect to make sure we weren't being completely ridiculous.
DickyC said:
Shaoxter said:
I'm looking at doing the same thing, do you mind posting their details?
I've had some quotes from architects, most of them were pie in the sky figures. There was one reasonable guy who quoted £2.5k, came round and measured everything, sent me some initial drawings and then disappeared off the face of the earth without charging me anything.
oakleygreen-conservatories.co.ukI've had some quotes from architects, most of them were pie in the sky figures. There was one reasonable guy who quoted £2.5k, came round and measured everything, sent me some initial drawings and then disappeared off the face of the earth without charging me anything.
Oakley Green Conservatories
Thatcham, Berks
I think they have a branch near Bath or Bristol as well but they cover the whole of southern England.
Have you read Equus's post above? I may only just have made it in time.
were now approaching the finishing line for our extension, project started mid September 23. 8 x 3 single story extension, velux windows in the roof, bi-fold doors and window on the new rear elevation. Conservatory removed, drains / sewage relocated, old wall taken out right across the back of the house, steelwork in, old kitchen stripped, electrics and plumbing re-instated and new walls, ceilings & plasterwork to what was the old kitchen / dining room ready for the kitchen fitters who moved in this week. Rear garden paved to create a patio right down the side of the house to form a new path all the way to our existing drive.
All in that's cost us 2.5k a sq m, circa 60K, (paved patio was 10 x 3) to this point. Kitchen units, fitting and appliances will be extra on top of that.
Local builder who has taken care of everything, organised all the associated trades and worked closely with the kitchen manufacturers to make sure everything will be in the right location. We've had very little involvement, chose the appliances and a couple of light fittings but otherwise the builders been excellent (fingers still crossed). We hadn't done anything like this before so were happy to take everyone's best advice. so far, that's worked very well.
All in that's cost us 2.5k a sq m, circa 60K, (paved patio was 10 x 3) to this point. Kitchen units, fitting and appliances will be extra on top of that.
Local builder who has taken care of everything, organised all the associated trades and worked closely with the kitchen manufacturers to make sure everything will be in the right location. We've had very little involvement, chose the appliances and a couple of light fittings but otherwise the builders been excellent (fingers still crossed). We hadn't done anything like this before so were happy to take everyone's best advice. so far, that's worked very well.
So I've had the Architects visit now, fees are as follows, stage 1 & 2 preparation and briefing & concept design £1500 stage 3 spatial coordination £1500 so £3000 total.
Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
Milner993 said:
So I've had the Architects visit now, fees are as follows, stage 1 & 2 preparation and briefing & concept design £1500 stage 3 spatial coordination £1500 so £3000 total.
Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
what size is the extension now going to be?Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
Audis5b9 said:
Milner993 said:
So I've had the Architects visit now, fees are as follows, stage 1 & 2 preparation and briefing & concept design £1500 stage 3 spatial coordination £1500 so £3000 total.
Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
what size is the extension now going to be?Having the architect over had the desired outcome, he came up with an idea that my wife and hadn't even considered.
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
With the improvements discussed this home will likely become our forever home, unless we come in to some substantial money.
Now looking towards the next stages, once I've signed a contract I'm looking at 8 to 10 weeks at the planning stages, which should be long enough to sort out a building contractor.
my current master bedroom is about 20sqm so the new master will be equal to this + an ensuite which is currently our family bathroom.
The kitchen extension will I suspect be of equal size, so could be around 40sqm in total.
z4RRSchris said:
double that budget
Well it’s already gone from £60/70k to £100k, and the architect hasn’t drawn anything yet, with no tenders, and before any considerations on finishing……Double the initial estimate really does seem to be a reasonable start. £150K to 2nd fix, and than its all up to the OP how mad to go on finishes etc 
. You think a two story extension is going to be around £200k, that seems very expensive.
Even if you worked on £4000 a SQM that's a £160k.
All price guides suggest between £1500 and £3000 a SQM, the second story should be around £1250 to £2500 a SQM, I guess it all comes down to finish at the end of the day
Only one source but you can find plenty more articles quoting similar numbers.
https://www.myjobquote.co.uk/costs/double-storey-e...
Even if you worked on £4000 a SQM that's a £160k.
All price guides suggest between £1500 and £3000 a SQM, the second story should be around £1250 to £2500 a SQM, I guess it all comes down to finish at the end of the day
Only one source but you can find plenty more articles quoting similar numbers.
https://www.myjobquote.co.uk/costs/double-storey-e...
Edited by Milner993 on Wednesday 24th January 21:22
Milner993 said:
We're now looking at having a new two storey extension with a new master bedroom built above a new open plan kitchen and family room with a re configuration of the first floor internal layout.
This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
That sounds vaguely similar to what we did in 1H22 except we abandoned the upstairs re-config as it would have meant a big steel across the house and too much disturbance as we planned to stay in the house while the work was going on. In the event we got chucked out for 6 weeks anyway - we'd have probably been OK but we had the stairs moved and my wife had an op on one of her legs so wasn't up to clambering a ladder!This would now allow me to keep my house as a five bedroom property but I would now have five double bedrooms two with ensuites and one good size family bathroom.
The kitchen would be open plan with large bifold doors and an island to keep the wife happy.
Where I wanted to keep the budget to about £60/£70k this has increased to £85/£100k.
Anyway, our build quote was £118K+VAT - I added it all up once done and we were pretty spot on £200K (inc VAT). Build quote did include all new windows and doors for the house, and new boiler and hot water cyl. Builder had quoted based on basic version of everything (because that level of detail hadn't been spec'd by the architect).
So things like oak staircase and doors were extra. Bit more electrical stuff, 'designer' vertical rads etc etc.. Then more for the kitchen (+£15K, and could have easily doubled that) , we decided to have the roof replaced as they were cutting into it anyway (+£10K) and I'd never been happy with it. They destroyed the garden so we had quite a bit of hard landscaping, new fencing etc. +£10K. Flooring £6K.
In my head I was thinking the whole thing was going to be £250K and it would have been if we'd done the upstairs so overall I was OK with the cost.
Milner993 said:
I guess it all comes down to finish at the end of the day
We’ve just ordered the shower tray for the en-suite in the new section of the house. Ended up going for a 1200x1200 square tray in black…….Cost per square meter guides are pretty good for the shell, but the finish can easily push beyond any budget. Milner993 said:
So I've had the Architects visit now, fees are as follows, stage 1 & 2 preparation and briefing & concept design £1500 stage 3 spatial coordination £1500 so £3000 total.
To be clear; that doesn't include technical design (Building Regulations/construction drawings; Stage 04)?Does it include measured survey of the existing house, or are you expected to sort that yourself, separately?
Structural Engineer's costs (if required)?
You also need to allow application fees, of course (Householder Planning Application is now £322, if submitted via the Planning Portal; B.Regs varies from Authority to Authority but is likely to be circa £1,250 for both plans checking and inspections).
Here are the three stages of planning by the Architect
S1. Preparation and Briefing (Project Brief)
This stage of the project would include: - • preparation of project brief including spatial requirements; • measured and photographic site survey; • drafting the existing plans and elevations;
S2. Concept Design (Architectural Concept and Planning Application)
This stage of the project would include: - • architectural concept design; • reviewing the concept design against the project brief; • client design reviews • preparation and submission of drawings for the planning application - OS Site Location Plan @ 1:1250 and Block Plan @ 1:500 Existing Ground Floor, First Floor and Roof Plan @ 1:100 Existing Front, Side and Rear Elevations @ 1:100 Proposed Ground Floor, First Floor and Roof Plan @ 1:100 Proposed Front, Side and Rear Elevations @ 1:100
S3. Spatial Coordination (Building Control Application)
Following a successful Planning Decision Notice, we would prepare an application for a ‘full-plans’ Building Regulation application. This stage of the project would include: • Spatially coordinating architectural and engineering drawings; • Preparation of the outline specification; • Preparation and submission of drawings to the local Building Control: Site Location Plan @ 1:1250 and Block Plan @ 1:500 Existing Ground, First Floor, Roof Plans and Elevations @ 1:100 Proposed Ground, First Floor, Roof Plans and Elevations @ 1:100 Proposed Ground, First Floor, Roof Plan @ 1:50 Proposed Section with explanatory notes @ 1:50 Monitoring of the application on your behalf; Liaison with any other consultants employed by you at this stage (e.g., structural engineers, energy assessors etc…).
Please note – Once we have completed stage 3 of the RIBA Plan of Work 2020 and receiving a successful building control approval our work will be complete and usually the builder/ main contractor will take on the role as Project manager to see the construction through to completion, if any further drawings are required after stage 3 then we can discuss these and provide a separate fee for you to consider or alternatively if you would prefer that I provided a Technical/working drawings package then I would be happy to provide another fee quotation to cover this. Our fees are inclusive of general disbursements such as internal printing costs but exclusive of local authority application fees such as planning and building regulations, OS Maps licences (used for site and location plans) which we will require to pay for before purchasing/submitting. Should there be any additional work to those listed, then we can discuss these and provide a separate fee for you to consider
S1. Preparation and Briefing (Project Brief)
This stage of the project would include: - • preparation of project brief including spatial requirements; • measured and photographic site survey; • drafting the existing plans and elevations;
S2. Concept Design (Architectural Concept and Planning Application)
This stage of the project would include: - • architectural concept design; • reviewing the concept design against the project brief; • client design reviews • preparation and submission of drawings for the planning application - OS Site Location Plan @ 1:1250 and Block Plan @ 1:500 Existing Ground Floor, First Floor and Roof Plan @ 1:100 Existing Front, Side and Rear Elevations @ 1:100 Proposed Ground Floor, First Floor and Roof Plan @ 1:100 Proposed Front, Side and Rear Elevations @ 1:100
S3. Spatial Coordination (Building Control Application)
Following a successful Planning Decision Notice, we would prepare an application for a ‘full-plans’ Building Regulation application. This stage of the project would include: • Spatially coordinating architectural and engineering drawings; • Preparation of the outline specification; • Preparation and submission of drawings to the local Building Control: Site Location Plan @ 1:1250 and Block Plan @ 1:500 Existing Ground, First Floor, Roof Plans and Elevations @ 1:100 Proposed Ground, First Floor, Roof Plans and Elevations @ 1:100 Proposed Ground, First Floor, Roof Plan @ 1:50 Proposed Section with explanatory notes @ 1:50 Monitoring of the application on your behalf; Liaison with any other consultants employed by you at this stage (e.g., structural engineers, energy assessors etc…).
Please note – Once we have completed stage 3 of the RIBA Plan of Work 2020 and receiving a successful building control approval our work will be complete and usually the builder/ main contractor will take on the role as Project manager to see the construction through to completion, if any further drawings are required after stage 3 then we can discuss these and provide a separate fee for you to consider or alternatively if you would prefer that I provided a Technical/working drawings package then I would be happy to provide another fee quotation to cover this. Our fees are inclusive of general disbursements such as internal printing costs but exclusive of local authority application fees such as planning and building regulations, OS Maps licences (used for site and location plans) which we will require to pay for before purchasing/submitting. Should there be any additional work to those listed, then we can discuss these and provide a separate fee for you to consider
Has everything been covered in the above though? Within stages 1 to 3.
If not what's missing?
From what I can see stage 4 has just been incorporated into stage 3
I have requested clarification from the architect.
If not what's missing?
From what I can see stage 4 has just been incorporated into stage 3
I have requested clarification from the architect.
Edited by Milner993 on Thursday 25th January 10:05
Edited by Milner993 on Thursday 25th January 10:14
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