Looking for a bigger house but what we want in our area commands a hefty price but we have spotted a house with potential for a two storey extension on the side. Looking at various websites but wondered if there was one really good one that most people go to/use (like stw for cyclists as there arent any others worth looking :-))
Just something to cover all bases from legal stuff,build,costs and everything in between. Just looking at the minute from a cost/budget perspective to see if its feasible, our house isnt on the market yet.

try looking on the local authority planning website for nearby properties and that’ll give you some ideas.
Where abouts are you?

To be honest you’d be far better to get a basic plan drawn up to run past a few Architects and Builders for budget ideas.

The two main issues are

1) would you get planning permission
2) How much would it cost

Both are quite hard to answer. If immediate neighbours have already extended similarly, then 1 is easier to answer (although never certain).

The answer to cost is almost always twice what you thought and then a lot more on top……..

There isn’t one I could find. DIYnot is ok for specific questions about building and planning but they don’t really like over general stuff, especially about price. The house builders bible book is quite detailed for costings and sets out the various process but you might not get much out of it without a plan.

For rough estimates I’d just use the £1000/sqm figure for a basic build, single storey. Double that for London or a high end finish. Add 50% for a second storey. That’ll get you a good starting point.

For rough estimates I’d just use the £1000/sqm figure for a basic build, single storey. Double that for London or a high end finish. Add 50% for a second storey. That’ll get you a good starting point.

I may be wrong, but I doubt that you’ll get anything like that number- from recent experience I’d say you’ll be lucky to get anyone decent quoting less than £1500+vat/sqm.

Our local authority’s planning portal has all applications on line to view, complete with plans, decisions, reasoning etc. Very useful.

I may be wrong, but I doubt that you’ll get anything like that number- from recent experience I’d say you’ll be lucky to get anyone decent quoting less than £1500+vat/sqm.

Probably something in between for basic building, I’d suggest, with kitchens/bathrooms/swanky finishes an additional cost. However, there are lots of different types of Builders, from your local adept, but slightly unreliable types who aren’t out to fleece you, to the larger firms, who have a lot of overheads. Take yer pick!

Agree with vinnyeh above re costs. m2 cost would not include external works either. Depends where you are though obviously. I would always say use a good Architect (I would say that!). Tell them what you want, how you want to use your house, your budget and timescales. Give them some images of the sort of thing you like (in keeping/modern etc). Get a couple of Architects to give you fee proposals and base your decision on this and how you feel about them. Costs include the build, VAT, contingency, statutory fees, professional fees including Architect and structural engineer – it adds up.

Thanks for the replies. I can do a lot of the internal work myself so i was kinda looking at the cost of footings,block work, drainage,roof,windows,steels for integrating to existing house if necessary and services. I see a lot of stuff stating a minumum of £1000 psqm but does that mean everything done but the furniture and decoration so essentially a fully plastered shell with services in place?

I’d say the £1000/sqm is a bare minimum figure. That’ll get you it built, plastered, basic electrics, etc. It soon creeps up if the site is tricky, or the build is complex, roof lights, fancy finishes, kitchen.