Typical cost of side/rear extension? Post Reply

[onerachel]

Hello. We are hoping to start building works on our house (typical Victorian terrace) soon. We are doing a side/rear extension, including adding a WC and small utility room, knocking through the first floor loo/bathroom to make one family bathroom and the house also needs re-wiring, all new floors and re-plastering/decorating. The building tender process has been quite painful and I also think our architect may have over designed things leading to high costs. Would anyone mind sharing their building costs for similar works please? I would be very grateful for an idea on what is standard in the area for this type of project. Many thanks.

[Sarahsea]

I've sent you a PM.

[Decimus Design]

Hi Onerachel,

In my experience it's rather difficult to define a "typical project", the cost of a residential development will be mainly determined by :

- Square meterage (new + refurbished)

- Design (you are correct.. some designers will over design/over specify.. this is often done to impress/deliver a good product for clients, but sometimes {sadly} it's done to increase fees.. )

- Finishes - perhaps have a look at what has been specified as floor finishes, sanitaryware, switches and sockets, light fittings etc etc. Spend a bit more time on research and get the "look" for less (your designer should be doing this).

- Builders - some builders are genuinely more expensive than others, when going out to tender on my projects I sometimes get a difference of up to 15-20% between builders. Sometimes builders are expensive because they are good (i.e. better finishes, management etc etc) but sometimes they are just expensive because of their reputation and because they know they can be. (expensive)

If you are concerned about the project being overvalued and paying over odds I would consider :

- Getting your current design and tender prices reviewed by a separate (independent) designer/architect or a quantity surveyor.

- Or go out to tender again to different builders (let me know if you need builder recommendations)

I hope this helps and good luck with your project.

E
Decimus Design
www.decimusdesign.co.uk

[onerachel]

Hello E. This is really helpful - thank you. I would be very grateful for any builder recommendations you have.
Many thanks, Rachel

[Decimus Design]

Hi Rachel,

You are welcome.

Try RM lines builders (http://www.rmlines.com/) speak to Tom. Or Totus construction (http://totus.construction/) speak to Andrew or Vinny.

If you get stuck, I'd happy to review your tender drawings/specification of works. I might be able to find savings and cost improvements. My email is erat@decimusdesign.co.uk

Regards

Erat

[SWpoet]

I saw RM Lines being recommended, and I'd like to echo that - they just did a kitchen refurb and small extension for us and we thought they were very good.

[actuallyadad]

Look the basic summary is it costs loads. Always way more than you think. Who knew you can spend 300 quid on a tap?

Builders are always annoying an unprofessional. The whole thing is a massive stress and I would not bother doing it again.

Lots of quotes will start low, and then get bumped up for ridiculous reasons "oh - you want skirting boards? that's not in the original quote..."

The answer is it depends a lot on the structural side - if you want to pillars that's more steel so more money. Party wall awards (annoying neighbours) that's another 2 or 3 grand. Even paint is amazingly expensive.

Mine was about 100 grand, plus 5 grand for bifolds. Then the actual kitchen ft out itself is about 35 grand or so. And the flooring and underfloor heating is another few thousand. Overall it cost LOADS!

[sills21]

We are about to embark on a similar project in Clapham South, and I just wanted to say that the advice on this post is really helpful!

Thank you.

[szerma]

Having gone through a similar project ourselves and having had experiences of builders good and bad, I would haphazard a guess that you are looking at £70-£80k plus for building work alone (as in not including the kitchen, taps, bathroom furnishings etc).

Beware of builders who are too cheap! They could just be trying to build out their portfolio / are new to the area / are a one man band hence the lower price, but always always go for people that someone you know or trust have had good experiences with. The cost can vary even for good builders though - if you go for a reputable company who will hire a PM and has big company overhead that will be a fair bit more expensive than if the builder himself is the company and the PM.

I haven’t used them myself but loads of my friends have had very good experiences with PVA builders, but they don’t take on small jobs (yours would be the right size for them though).

If you want any advice on what not to do with builders, feel free to PM

M

[robinm]

We’ve literally just moved back in after ours. We’re very happy with it and it does change the dynamic of the house!

Ours (mid sized Balham terraced house) came in at about £100k - that’s all in.

Be mindful of costs like moving of boiler, moving of gas metres, skip licences, the garden getting trashed etc. Try to think of everything you want them to quote for as anything else will come under an exaggerated day rate - we forgot to ask for splash back tiling as an example.

Happy to recommend the builder we used in PM.

Robin

[LWade]

Hi, I do this for a living and have completed about 15 similar projects. I would say about £65k as a guide price based on my Victorian terrace houses all in the Wandsworth and Tooting area. Why don’t you call the guys who work on all my projects, Clive is the main contact on 07966 476862. They can take a quick look at the plans and it shouldn’t be as painful as you’ve been experiencing so far! Message me if I can help you any further.

[linda73]

Hi Rachel,

When we did our rear extension and loft conversion last year, we used Green life Contractors Ltd (www.greenlifecontractors.co.uk) I would really recommend them!

0207 736 2006 / 07403455558

But I would guess that your work would cost about £80k? But that's just a guesstimate compared to what mine cost.

[Ensoul.co.uk]

Hi Rachel, happy to have a chat if this is still relevant; i can give you some estimates over the phone based on the anonymised tenders we have run previously, all the best, Mike Lander, Director, Ensoul 020 3637 0700

[Emma Green Design]

Hello Rachel,

I'm a local interior designer and have worked on a number of side return projects with clients, whereby I organise builders, architects and manage the whole process including the interior design aspect. If still need help and you would like to contact me to discuss how I can help, my contact details are below and images of a previous side extension can be found on my website (and others I can show you personally).

Kind regards,

Emma
020 7738 0637
http://www.emmagreendesign.com/portfolio/
emma@emmagreendesign.com

[aurahomes]

Hi Rachel.

Sorry, long post alert!

You need to be careful with this question as every man and their dog will have an opinion based on their wildly differing schemes and experiences.

There is no such thing as a 'typical' side return and i'd suggest you ignore anyone that hasn't seen your design/schedules/scope of works/site constraints/timeframe.....you get the idea.

I spent last week on the Ask An Expert feature at the Grand Designs LIVE exhibition providing free design consultations and the question of budget/cost came up a lot!

The truth is you will never know the cost of your project until you've got a full design package and have 3-4 tender prices from contractors. You could also pay a Quantity Surveyor to cost your project and give a baseline for comparison but this desktop appraisal doesn't portray what is available in 'real-life' (how busy/profit margins/leadtimes/standard of finish/reputation/site management etc)

I also guarantee everything will be more expensive that you first thought!

If you are employing an architect/QS/designer and are paying for a tendering service where they analyse the tender returns and negotiate with your contractors, they should be helping to bring your scheme down within budget. This is where the professional consultant should not only be adding value to your scheme, but working with all parties (including you) to design what's realistic within your budget.

Were you open with your budget to your architect? I often ask for a clients budget and get a very coy answer. As designers we need to know what to design within and manage expectations.

What i would say is that if what you've described is a whole house refurb ("the house also needs re-wiring, all new floors and re-plastering/decorating") together with the side and rear return and minor alterations will certainly cost £100k+.

I'm writing a blog currently (to be released in the coming weeks) that should help homeowners get a realistic idea of what to budget for their home improvement works based on floor areas. Try this for a high level appraisal (cost to face of wall finish, kitchen excluded)

New single storey extension cost between £1500-2500 per m2 (broad range, I know)
Major structural openings - £5-10k (depends on complexity)
Internal refubishment (back to brick, plastering, wiring, finishes) - £750 per m2
Cosmetic upgrades - up to £500 per m2 depending on finishes
Chimney removals £2000-5000 per chimney
mid-range 3-piece bathroom - £3000 'shell' plus £3000 sanitary ware and finishes
Kitchen.....depends on taste!

I'm sorry that I couldn't give a definitive answer here but there are just too many variables.

I'd be happy to discuss your scheme further on the phone if you send over your details and design package to benrichards@aurahomes.co.uk

Kind Regards
Ben Richards
Director
Aura Homes