First Extension - background reading

[John145]

I'm thinking of extending our property and was hoping to get some advice on books to read so that I can increase my basic understanding to avoid the avoidable and find the best value for my investment.

We have a semi that is currently over 3 floors with the master bedroom in the roof. It's a new build (3 years old) and I was thinking a 3 part extension:
- Full height master bedroom (currently there is a small dormer for a window but most of the bedroom is restricted by the eves) to allow an en-suite and better storage
- Garage/office to the side - maybe even a full height extension to go from 3 bed to 4/5
- Rear extension, single storey and to the side to connect the office to the rest of the house and increase the square footage of the ground floor by about 10%

Guessing 100-150k!

[John145]

Cerbhd said:

Always worth getting a local estate agent around to discuss especially if it's not your forever home. They can give a good idea of values before and after.

Our next door neighbour has been through the process (adding a half dormer and extending the rear) and needed valuations to secure mortgage money, they've added 25% which has more than paid for the work! This is why I'm particularly keen, it'll be a great experience to manage and may even go as far as effectively paying me a salary to manage it part time.

[John145]

Lesgrandepotato said:

I'd be nervous of doing that on a new build, there is a reason the developer didn't... you'll find a massive difference in costs depending on locality and your involvement. If you are happy to get trades in it'll be much cheaper. If you need it turn key you'll pay for that.

I should expect all the work will be undertaken by tradesmen with an employed architect and possibly myself as PM - hence the request for background reading material.