Rear extension??

[apbremer]

Would any kind soul know the very approximate cost of a ground floor rear extension some 6m. wide and 5m. deep, so 30 sq. meters of simple block construction rendered, flat roof, half width window to normal height, simple electric connections and no drainage problems?? Admittedly very early days without proper plans etc. as yet, we have two rough quotes of what I think are ridiculous figures. Thank you.

[Jeremy]

I don't know... but given that a side return extension (say 1.5m x 6m) can cost 40K before you've even starting thinking about the interior... a construction three times that size is not going to be cheap.

[bonaome]

Yes, about ?40k for a side-return extension. I believe what actually makes it expensive is anything that requires going out beyond the existing foundations. So what you are describing sounds to me like it would be very expensive.

[Tr?]

Your relationship with your neighbours?

apbremer Wrote:

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> Would any kind soul know the very approximate cost

> of a ground floor rear extension some 6m. wide and

> 5m. deep, so 30 sq. meters of simple block

> construction rendered, flat roof, half width

> window to normal height, simple electric

> connections and no drainage problems?? Admittedly

> very early days without proper plans etc. as yet,

> we have two rough quotes of what I think are

> ridiculous figures. Thank you.

[motorbird83]

It?s expensive. A good rule of thumb is 1,500 psm so for an extension this size the pure construction costs would be 45k excluding VAT. Other things that are probably included in your quote:

1. Fees: architect fees for planning drawings, measurement surveys, engineer drawings, building control plans and fees etc will be between 5k and 10k (depending if you use a fully qualified architect or if you get the builder to use his in house design team).

2. New windows and doors: if you want velux windows, and basic bifold doors add around another 4-5k for that

3. The quote might also include some of the new electrical fittings (LV spot lights, facings for electrical sockets and switches, etc). Depending on what they are assuming, add another 2k

4. Do you need to move your boiler? Did you say you want to install a loo under the stairs? And 1k for moving the boiler (more if you need to replace it) and 2k for the under stairs loo

Other costs not included in a typical quote for a builder but should be part of you budget is;

1. Cost of new flooring throughout (not just the new space but integrating it with the old). The installation costs should be in the quote but not supplying the floor. Without know the final size of your rear room post extension its hard to guess what this will be but assume a minimum of 30 psm

2. Do you want underfloor heating? For an extension that size, that will be an addition 2k at least for a water-fed system and will be on top of the basic spec that 1,500psm mentioned above

3. The cost of any fancy lights you want (under cabinet lighting, over counter lighting etc)

4. The cost of a new kitchen (assuming you are getting a new kitchen).

Total budget for all the extras, 20k would be pretty middle of the road spec.

So I?d budget a minimum all in of 85k for something that large. That?s assuming no new manhole needs to be done with Thameswater, and no garden work (your garden will be ruined post-extension).

[Salsaboy]

What motorbird said but I'd round it up to 100k for the things that will go wrong.

[LondonMix]

Yes, add in a 10 percent contingency and cost of doing up the garden to Motorbird's post and you are quickly pushing 100k.

[red devil]

VAT is a killer, another ?20k on top of the ?100k.

How does this all stack up with the ''ridiculous'' figures you were quoted apbremer?