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How much did your extension end up costing?

7 years ago

last modified: 7 years ago

We are in the process of submitting plans for a rear ground floor extension, first floor extension above existing garage and a loft conversion. We will be going out to obtain builder's quotes once the plans are passed, but just curious of costs. Would be interested to know peoples experience of extension quotes. How much contingency do you keep aside for over spends?

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Comments (5)

PRO
User
7 years ago
This is quite a good website, fairly informative about general costs. Just remember, that this is the build cost, it won't include a kitchen, bathroom, flooring, lighting etc.

We always have a contingency of around 20%, that way you know you should be covered when things out of the ordinary crop up, and they always do, especially on old houses. Householder quotes
PRO
London Urban | Design & Build
7 years ago
last modified: 7 years ago
We always suggest a few things -

1. Be as clear about your vision for what you want - the devil is always in the detail.

2. Have as clear a scope of works that allows for as much as possible from your vision. Also have clarity on what you are going to supply or if you leave to your contractor.

3. Get decent construction drawings which incorporates as much of your vision as possible. The better the plans, the easier and clearer it will be for your building team.

4. There are always going to be unknowns / changes - 10% to 15% for a contingency should be about right if you have done points 1 to 3!

5. Find a building partner that will work for / with you to value engineer and help find savings to cut costs so you don't need to tap into your contingency - It's a lot of money you will part with and you need a trusting relationship from the outset.

6. Make sure there is financial transparency and project planning with your build partner - time does cost money and delays cost stress you don't need!

Good luck with your project!
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PRO
Vita Architecture Ltd
4 years ago
Hi, we've done a number of builds and extensions all of which range between £2k-4k per sqm. Contingency wise, we typically advise 10% on new builds but if it's a refurbishment or contains particularly high risk unknowns, that can go upto 15-20%. We've written an article on this too if you wanted to take a look!

http://www.vitaarchitecture.com/how-much-does-an-extension-cost/
PRO
AC Design Solutions Ltd
4 years ago
I can arrange for a building quote if you message me more details.
HU-431814713
2 years ago
Using guided prices is always difficult because of the different regions in the country, specification and sizes, plus knowing what has been included or excluded within figures quoted i.e. kitchen fit-out, bathroom sanitary ware, VAT etc.

But if you considering an extension you should try www.CostMyHome.co.uk. Its free to use and allows you to draw your extension outline, so its based upon your specific property, specification and requirements. They give you a budget price but also itemised estimate too, doesn't cost you anything. Video below might help explain how it works.

To find out how much your extension would cost, simply type in your postcode, find the property number, draw the outline of your extension and select what works you desire. Within a matter of split-seconds you’ll be presented with a cost for your renovation or extension project. It really is that simple.

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