Addition to existing extension

ollie_h1

I am in the process of buying a Victorian semi detached. The property is a standard layout with two bedrooms and a bathroom upstairs and two reception rooms downstairs in the main part of the building, to the rear of the building is the Kitchen. About 10 years ago, a modern single storey extension with a flat roof was added to the rear of the property off of the kitchen.

I have seen several similar properties with a double storey extension in the same place as my single storey.

I want to know how much roughly it will cost to build on top of the existing single storey extension, adding an extra bedroom above with a pitched roof. I will source some of the building materials myself (bricks, tiles etc). The room will be 3 metres by 2.5 metres (so not massive, maybe a large single bedroom). I will do the plumbing work and a close relative is an electrician and I know a excellent plasterer who will charge me very little. I will also do all of the decorative work myself.

So I guess what I am asking is, how much will it cost for planning, design and labour to get another storey on top of the existing single storey extension (basically to get the shell water tight and I do the rest).

I have heard conflicting reports of anywhere between £1k and £2k for design and planning and £5k and £20k for the rest.

Just to clarify, I believe that the existing extension is suitable for this as my surveyor said the walls are cavity with a breeze block inner so could take the weight of another storey. The house is on the Surrey/Hants border so I appreciate my labour costs are going to be higher than in other areas of the country.

Any help would be really appreciated.

Ollie

grassit

Its the foundations under the extension that are key, not just the construction of the walls. You can have a study wall on shallow foundations, no problems. Can you get the previous extentions drawings, do the council keep records that far back (assuming there was a planning application, or build regs app). Get a builder to dig an inspection pit to be sure, and ask him for a quote. Then get another few and compare and contrast.

Best of luck.