New house build - "green" features

New house build - "green" features

Author
Discussion

Kudos

Original Poster:

2,674 posts

189 months

Wednesday 5th February 2014
quotequote all
I am (once again) looking at building a house. I may have found a suitable site.

This will be a fairly top end house (c5,500 sq ft, pool etc), so I’m keen to make sure it has the gadgets you’d expect. Fairly close to the top of this list is energy efficiency and cheap to run.

What are the must have technologies for a green house? I had looked into these a few years ago, but I’m sure technology has moved on since then.

Solar? Ground or air source? Anything else?

jdw1234

6,021 posts

230 months

Wednesday 5th February 2014
quotequote all
Top of my list would be:

Large garden
High ceilings
Ample parking with large garage doors
Staff/granny annexe over garage
All rooms decent sized
Ability to chose kitchen to my taste
High standard of finish and architectural detailing

I ams ure the above is all egg sucking stuff, but green gadgets wouldn't even be on my list of criteria.

As new builds are cheap to run anyway, the main thing would be an efficient method of heating the pool.

Finally, absolutely no solar panels. No no no no no.





cRaigAl205

298 posts

138 months

Wednesday 5th February 2014
quotequote all
As mentioned, I personally wouldnt go in for huge numbers of bolt on "green features"

Simple things like increased insulation and build quality (air tightness etc)can make a big difference. Building regulations are just a minimum requirement, and compared to other costs, increasing the thickness/quality of insulation is relatively minor, but will make long term saving. perhaps look into some of the standards out there, such as passivhaus etc (even if you dont fully commit, you can incorporate aspects.)

Maximise daylighting without overheating (louvers and roof overhangs can be useful for this- maximum sunlight in the winter when the sun is lower, but limits overheating in the summer)
Roof lights and sun tubes to get "free" daylight into areas which would otherwise rely on electric lighting.

Remember, good overall design and layout has an upfront cost, but will then keep paying off for the rest of the life of the building, whereas bolt on "green gadgets" have ongoing repair and replacement costs. I know quite a few people who jumped on the solar bandwangon, only to have the inverters die, and be left for months with a system doing nothing!

I would possibly add green roofs to my list, but I know they aren't for everyone! Obviously "green" but have other benefits to the building, natural insulation from the soil, etc

Craig

Edited by cRaigAl205 on Wednesday 5th February 14:12

Muncher

12,233 posts

264 months

Wednesday 5th February 2014
quotequote all
If the could be completely hidden from view I would add solar. I would also specify mechanical heat recovery and probably a ground source heat pump for the pool and to supplement your gas powered underfloor heating system. With LED lights and very good insulation I don't think the running costs will be that substantial on that kind of house anyway.

dxg

9,369 posts

275 months

Wednesday 5th February 2014
quotequote all
MVHR

hahithestevieboy

845 posts

229 months

Wednesday 5th February 2014
quotequote all
Some good advice above. I would probably not get any green gagetry or go for high rating on BREEAM of the code for sustainable homes as they are a load of political green religion rubbish (that can often help with planning as planning are into that stuff).

I would however agree on a fabric first approach like passive haus (to save money on energy it is best to not use/need it in the first place) as this has intrisic value and will make the house more comfortable to live in as well as cheaper to run.

I would however use some caution because if this house is a spec development to sell on, you are not able to amortise the greater capital cost and it could be very unlikely that you get your money back in terms of a higher selling price. This is a marketing issue however and you should contact your estate agent for a steer on this. Substantial annual savings could be made on heating and electric bills on the house type you describe - i.e large areas/volumes with relatively low occupancy. I would suspect your target market would be unimpressed with green for greens sake but would be more likely to be convinced on economic and/or comfort and/or longevity/quality arguments.

Everyone loves a gadget though so: I would avoid ground source heat pumps (especially if you are not going the passive haus route) and use gas underfloor heating.
Consider an air source heat pump for the pool. Put the pool indoors, super insulate and you can get a concrete floating "bottom/cover" for the pool that makes the pool a variable depth at the press of a button. This is concrete with a foam core so it has fairly neutral boyancy but if it is raised, it also keeps the heat in the water and allows the space to be used for something other than swimming and makes a fool proof cover for the pool so is totally safe if there are kids about.
You could have a fancy heating system giving zoned control over i-pad type interfaces.
Tripple glazed windows can be shown off, improve efficiency and reduce cold spots near windows that cause convection drafts.
MVHR is a must.
High airtightness.
Excelent insulation and detailing.
LED lighting.
Consider some form of rainwater harvesting but probably not really worth it.
Sustainable drainage will be forced on you by the planners/building regs.
Sedum roof - I would say only where it can be seen such as a ground floor flat roof (would you pay more for a house with a green roof).

Personally, I would build the building heavy with high thermal mass and concrete stairs and upper floors and stairs and all of the other stuff mentioned by others.


Muncher

12,233 posts

264 months

Wednesday 5th February 2014
quotequote all
I would certainly look for a concrete first floor in future, in fact I would look to cast the entire structure in solid concrete and insulate externally.

kiethton

14,230 posts

195 months

Wednesday 5th February 2014
quotequote all
I would look for SMART features in terms of both energy and multimedia:

Wired cat 5/6 for multimedia systems but:

heat sensors in each room linked to the central thermostat so rad's/underfloor heating circuits can be bypassed if the room isn't in use/is at the right temperature. A system like Hive linked into the same if possible.

Room by room electricity monitor which can go into the central plant room/app which allows you to shut off power to specific plug sockets/rooms when not in use.

An energy efficient way of heating the pool - ground source?

Nice log burner in the main room - free logs!

Good insulation/triple glazing?

Brother D

4,164 posts

191 months

Wednesday 5th February 2014
quotequote all
I always thought http://retherm.com/ are a good idea - hot water leaving the shower heats the cold incoming water before it goes down the drain.

(On the shower front an enclosed shower (including top) seems like a smart move. Standard air faucets/shower heads to cut down on water usage.

I know grey water is 'grey area', but I always thought reusing shower water to flush toilets is a good idea - using drinking water to flush a toilet just seems wrong to me.

Triple glazing - I so wish my current place had this...

barryrs

4,795 posts

238 months

Wednesday 5th February 2014
quotequote all
As said fabric first and as its a sizable dwelling it might be worth considering a micro CHP boiler so that your boiler also generates electricity back to the grid.

was8v

2,003 posts

210 months

Wednesday 5th February 2014
quotequote all
Don't think in terms of "green gadgets" take a holistic approach to making the house to use as little energy as possible.

Take a look: http://www.passivhaus.org.uk/page.jsp?id=17

There is only one direction energy bills are going. In 20 years time who knows where we will be with climate change - low energy houses are and will be highly valued.

Build in PV on the roof and a wind turbine down the garden as gadgets. There are people making £10k+ a year from selling back to the grid.

Imagine if that heated swimming pool cost you nothing to run?

Muncher

12,233 posts

264 months

Wednesday 5th February 2014
quotequote all
Brother D said:
I always thought http://retherm.com/ are a good idea - hot water leaving the shower heats the cold incoming water before it goes down the drain.

(On the shower front an enclosed shower (including top) seems like a smart move. Standard air faucets/shower heads to cut down on water usage.

I know grey water is 'grey area', but I always thought reusing shower water to flush toilets is a good idea - using drinking water to flush a toilet just seems wrong to me.

Triple glazing - I so wish my current place had this...
Good idea but by the looks of it I'm not sure how effective it would actually be, if the water flows straight through it is going to transfer very little heat to the cold water loop around the pipe.

hahithestevieboy

845 posts

229 months

Wednesday 5th February 2014
quotequote all
barryrs said:
As said fabric first and as its a sizable dwelling it might be worth considering a micro CHP boiler so that your boiler also generates electricity back to the grid.
Small chp's arent that efficient though and can get feindishly complex as a system.... personally, I'm not sure i'd bother with that unless the house for some reason had a high baseload requirement for electricity and ran aircon in the summer.

barryrs

4,795 posts

238 months

Wednesday 5th February 2014
quotequote all
I was thinking of the Baxi which i assumed (maybe incorrectly) was a pretty simple setup? - http://www.baxi.co.uk/renewables/combined-heat-and...

Ive never used one personally but the rep (obviously he would say this) seemed to think it was quite worthwhile on larger dwellings.

Kudos

Original Poster:

2,674 posts

189 months

Wednesday 5th February 2014
quotequote all
Thanks everyone, some very useful advice.

Full insulation is a given. I've recently completed a conversion of an old 7 bed house into 4 x apt's and commercial unit. We spent a fortune on insulation etc and my EPC surveyor couldn't believe the score. The tenants are happy too.

Is there much of a price difference in double/triple glazing? I thought it was a bit of a gimmick? It could be useful as proposed site is near an airport.

My current house is 1935'ish and although we upgraded significantly, it's still drafty in places.

The price of fuel is only going one direction (I own an oil company, but this is still a concern), and with the wife and 2 young kids in the house all day I want the place to be warm and not worry about cost to heat. For this reason I want underfloor heating. If I heat by gas, will this not be expensive? Thats why I thought ground/air source, solar or wind could be an option.

Log burner is def on the list

fuzzymonkey

441 posts

240 months

Wednesday 5th February 2014
quotequote all
Why are some people very keen on concrete? Is it much more warmer than bricks?

barryrs

4,795 posts

238 months

Wednesday 5th February 2014
quotequote all
Concrete has an excellent thermal mass and will hold heat and realise it back into the dwelling.

With regards to triple glazing.

We recently priced some 36mm triple glazed units and the difference on a 3 bed consisting of 8 windows and 1 back door was £280 ish.

U-values went from 1.35 to 0.8 which is a decent gain for not much outlay IMO.

inman999

31,739 posts

188 months

Wednesday 5th February 2014
quotequote all
fuzzymonkey said:
Why are some people very keen on concrete? Is it much more warmer than bricks?
It will have a higher thermal mass as the insulation is usually external. So in theory the temperature will remain stable with benefits in both the summer and winter.


mildmannered

1,231 posts

168 months

Thursday 6th February 2014
quotequote all
I should imagine concrete floors are better in terms of acoustics too?

Spare tyre

11,284 posts

145 months

Thursday 6th February 2014
quotequote all
I'd think about floods.