New extension? How to identify a good (not bad) building firm.

So how do you separate the good building firm from the bad? How can you be sure that they’ll do a good job for you? We give a few pointers here. And if you want to sanity check their prices – then scroll to the bottom for the best advice possible…

A professional-looking quotation with detailed information

A handwritten note, a single printed sheet, the final price in the body of an email is NOT a good start. You should want to see a smart looking quotation without any spelling errors. It should include detail – a breakdown – evidence that they’ve understood the job. The last thing you want is miscommunication that is uncovered too late into the job.

And check on ‘provisional sums’. There are some jobs that builders will sub-contract. There may be internal items that they don’t want to price because there are so many variables. Be careful that you’re not going to be hit with an unexpected ‘extra’ that hasn’t been budgeted for.

And payment terms – agree whether there’ll be stage payments. Will it be with each build phase or each month? A good builder will have the answers.

Good communication and presentation

The builder who is always prompt with email, text and phone replies is off to a flying start. Time-keeping, attitude towards answering your questions, even managing your expectations, are all indicators of how much they value your custom. Being honest enough to say that the quotation won’t be with you for X number of days, whilst not being ideal, suggests they’re going to be transparent with you. There’s no guarantee, but you would hope this diligence mirrors how they go about their work.


Endorsements go a long way. We all look at reviews. See what testimonials they’re sharing on their website and on social media. You’d be right to be wary of fake testimonials. Testimonial-gathering websites can’t always be relied upon. Ask to speak to the owners of projects previously completed by the builders.

Be wary too of photos of previous jobs on the website – there’s one image that must be a stock shot because we see it coming up on lots of building firm websites – and they can’t all have worked on it…!

A good building firm will be health and safety conscious?

As a result of Covid-19, health and safety is very much in the public domain. It’s not just a commercial or corporate issue.

Obviously you’ll want to know the builders will be working responsibly and the project will be Covid-19 secure. But there’s much more to it than that.

Builders should be up front about their health and safety measures because it affects you. As a ‘Domestic client’ you have health and safety duties under CDM 2015. The builder needs to be clear on the transfer of responsibilities. Can they demonstrate their plans for operating safely? Ask to see the kind of documents they work with. Risk Assessments, plans and policies. Ask to see their Public Liability insurance at the first opportunity.

Financial security

You both want the same thing. You want to be clear that there won’t be any movement on price – unless exceptional circumstances are stipulated. And the builder wants to be sure there won’t be any moving of the goal posts. A legal contract sorts all of this out. So agree all this at the outset. No job should start without a Notice of Right to Cancel form being handed over to you.

I should also comment on the difficult times we’re in. The builders have got to follow Covid-19 procedures. Jobs are taking longer as a result. Materials are going up in price all the time and there are shortages on key items including roofing – all causing problems and delays, which I explored in a previous article. So talk it all through with the builders – you may have to meet them half way. You want the work completed and they can’t be left out of pocket. A builder you feel you can trust will work with you to find a solution.

Oh… and then there’s this…

County Court Judgments… you’d be surprised how many building firms have them and continue to work, risking the credibility of the industry. Do your due diligence on everyone tendering. I’ll leave it there!

Most valuable test for a building firm

Check that their prices are in the right ball park. And that’s where Cost My Self Build comes in. As a client, Ian from Bristol, said having used our service, “The prices we received from the building firms varied massively. So having an independent evaluation of the costs involved in the construction of our extension helped enormously.”

It’s a simple process so long as you have all the floor plans and elevations. And there’s no obligation to go ahead once you have a quote for our service. So give us a call on 0117 916 7878 or upload your drawings here.