Please estimate my extension costs

5 Dec 2012
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United Kingdom

we are in the early stages of the extension process - we have had the architecht out, who is drawing up plans.

I live in West yorkshire (Leeds), and we are having a single storey wrap around extension.

It will go out 3m at the back, and 8m across. Along the side, it will be 2m wide and 4m long. My calculations are that it will be 32 square metres in total.

This will be our new large kitchen diner and a utility at the side of the house.

we will be having 1 new door, and 2 or 3 velux windows to let light in, along with some french patio doors at the back.

What sort of quotes should be we expecting? Taking into account the groundwork, brickwork, roofing, windows, doors, guttering, electrics, plumbing for kitchen, utility, and 2 new radiators, and plastering? I will probably be fitting the kitchen (cost dependant) and the flooring.

We need a structural engineer to calculate load for a steel beam.... not sure on costs?

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Don't the architect know, or had he just been given a blank cheque?

Tip: the "architect" does not just draw plans.
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Do architects provide accurate guide prices?

One of, if not the first question should be "How much have you got to spend?" Then the designer should design something to that budget.

The designer should know if the build can be bigger or smaller, how much the steelwork will add, whether any steelwork can be avoided, whether to have 3m or 4m bifolds or just some french doors and a window, and how much the chrome or white plug sockets will cost.

For most people costs are the driving factor.
agreed with woody, the architect is really expensive compared with a plan drawer for a good reason - they take everything into account with their designs, not just what looks nice. in many ways architecture is about people, not buildings. plan drawing is about buildings.
This type of extension tends to be a lot more because your existing kitchen floor may have to be dug out, you might have to move your services to outside and the water supply pipe might need changing. Also you will need a new ceiling in the kitchen. Plus the steel will have to sit on a column or brick pier which requires a new bit of foundation. Then there is the risk premium for the builder having to support the side and back walls, plus the extra foundation to dig down the side.

Just saying there are a lot of things that can bump up the cost of this type of extension.

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