As a rule of thumb you can add 50 extra to the build cost of a single storey extension.
Rough cost of ground floor extension.
These prices are for for a good quality extension.
The average build cost figures used by the extension cost calculator assume straightforward ground conditions and a.
Below we have broken down different elements of an extension build and the different kind of costs involved but the key underlying cost relates to the size of the extension being built.
Add on 10 15 for professional fees architect planning application building regs structural engineer 6 750 at 15 vat 9 000 double storey house extension cost 60 750.
House extension cost calculator are you looking for more space or thinking of buying a house and extending it yourself.
Two storey side or rear extensions are more cost effective than single storey extensions coming in at around 1 320 to 1 620 per m for a standard build so with this budget you could extend by at least 35m sufficient space to add a large kitchen and or living room extension on the ground floor with two new bedrooms and a bathroom above.
Building work costs depend on the results you re after but reckon to pay around 1 500 to 1 900 per square metre for basic quality.
There are different ways to break down the cost of your extension but here are some rough costs.
1 900 to 2 200 per square metre for good quality.
Basement extensions cost on average between 3 500 5 000 per m.
Well before you go dreaming of sky lights and kitchen islands take a look at our house extension cost calculator below to determine how much you may expect to pay for the labour costs in england and wales.
And 2 200 to 2 400 per square metre for excellent quality when building a single storey extension.
Our extension is 5m by 4 5m so 22 5 square metres.
In 2019 an estimate for the cost of a single storey extension is anywhere between 1 350 and 1 950 per m2.
See the bottom of the page for how much my extension ended up costing.
If it all depends how much does a single storey extension cost.
The cost of excavating beneath an existing property and supporting it whilst the structure is underpinning is expensive and the calculator uses a multiple of 3 x the average cost per square meter for an above ground extension.
The cost of a typical high spec glass extension is around 2 500 per m.
1 500 per square metre for upper floors extensions per floor.
A rough building cost would be 45 000.
In london and the south east this could be anywhere between 1 800 and 2 300 per m2.
So 30 000 50 45 000 for the basic build cost.
Speaking to our experts we have established that the basic price of building an extension is 1 100 to 1 400 per square metre.
The average house extension cost in london in 2019 is between 1 600 2 100 per m.