Why choose Cox Format?

  • A local family firm operating in Barnet for 40 years under the same name.
  • One stop shop for design, build and home finishings.
  • All of our trades are employed by us, many having started as apprentices.
  • Free kitchen design service when we build your kitchen extensions.
  • Barnet High Street office, open to the public. Come and visit us.
  • Free, no obligation quotes are usually issued within 7 days.
  • Customer feedback says we are reliable, trustworthy and affordable.
  • Trade discount on kitchens when we build your kitchen extension.


May 2019

Accomplished excellent work

Double Commas We recently completed an extension to the rear of our house. From the start of the design process through to the construction Cox Format demonstrated professionalism, expertise and customer service with a clear passion for their business. It was clear from the start that their purpose was to ensure the clients expectation and satisfaction were met and put in the time and effort to ensure their goal was met. From start to finish the project went smoothly. We had regular updates to review progress and discuss any changes. Any last minute changes were incorporated with ease. The work force turned up every morning at 7AM and were respectful and trustworthy and accomplished excellent work with paying attention to detail. Our home surroundings were protected to prevent any damage. We were impressed with the workmanship and the speed with which the work progressed. The workplace was always left clean, safe and tidy at the end of the day. Weve had an excellent experience with Cox Format and are very pleased with our finished product which was delievered on time and within budget. I would recommend Cox format as our expectations were highly met and quite simply stress free due to their organised and dedicated approach to their business.Double Commas

Marie McMahon

May 2019

Excellent work from start to finish

Double CommasRecommended by a friend. Excellent work from start to finish when putting a new kitchen into our property in Welwyn Garden City. Kitchen looks great with a very high quality finish. New decoration done throughout and the advice on colours / tidy state of the property at the end of each day was very much appreciated. Have already recommended and wouldn’t hesitate to do so again. Double Commas

D. Shirley

May 2019

Extremely happy with the service

Double Commas Cox built our loft extension; we were extremely happy with the service we received at all times. Work was completed in very good time and to a high standard, and everyone involved was friendly and professional at all times. We had a couple of minor hiccups, such as a dripping pipe, but these were rectified very quickly and without any quibbling. I would definitely recommend this company. Double Commas

Simon Spiro

April 2019

Great company with a lot of experience

Double Commas We chose Cox Format to do our loft conversation because they’re Which? Trusted Traders and we wanted a loft conversion done that required lowering some ceilings to make room. Cox’s team were excellent at managing all aspects of the conversion, from completing the council paperwork, to providing detailed quotes and timelines. Mark, Project Manager, took into account all of our requirements and provided a lot of flexibility with additional tasks that we wanted done, such as custom spotlights and additional electrics. He also provided us with a timeline of work to help us manage expectation. A major plus was how quickly and professionally they built the loft, choosing additional manpower instead of sacrificing quality. We were able to see everything as it progressed, and the builders were happy to answer all of our questions. Everything was solidly built, finished, and plastered to a high degree. Both the builders and the subcontractors involved worked to a high standard while taking care of our house. Cox gave us an estimate of eight weeks to do the loft conversion. Eight weeks later the loft was complete and Cox Format delivered us the Final Certificate to show that it had passed all inspections. The build went smoothly, and we highly recommend them to anyone who wants a hassle-free loft extension. Double Commas

Customer in Greater London

January 2019

Design and Build Loft Conversion

Double Commas We engaged Cox Format to design and build our dormer loft conversion. They made well thought out plans with our input and took care of the planning permission and the subsequent appeal. They communicated the start date and from then on were at work solidly until they finished. Arriving every day without fail at 0730 and getting straight to work. Starting at this time allowed us to discuss and take any decisions the team needed before leaving for work ourselves. The team were well presented, professional, polite and hardworking, paid good attention to detail and always tidied up before leaving for the day. The back-office staff produced a detailed quote and payment plan with an itemised list of any additional payments. I would absolutely recommend Cox Format for your loft conversion. Double Commas

Samantha & Jonathan
Shenley WD7

November 2018

Dear Peter

Double Commas We just wanted to thank you for all the hard work your guys have put into our project. The work was done to a very high standard and we are thrilled with the outcome. James, Graham & Mark’s inputs were invaluable to this project. Mark has given consistent support from beginning to the end – his professionalism was one of the main reasons for choosing Cox Format as our contractor. His promptness in dealing with issues was second to none. Both Graham & James exceeded our expectation as foremen. Their managerial & organisational skills on top of their craftsmanship were the catalyst for the success of our project. Also Graham’s carpentry skills are superb, which must be a real asset to your company.

Thank you again for all your support for the past 5 months. Double Commas

All the best,
James & Yoko

July 2018

Double Commas The whole project ran like a military operation and if things fell behind due to unforeseen circumstances Cox Format caught up with things by sending in reinforcements. There were regular site visits by the Managers and constant feed back. We received helpful advice throughout. We were very pleased with the work which was finished to a high standard and on time and all of the workmen were very obliging.Double Commas

Kind Regards
Danny Darwish

21st May 2018

Double Commas We just want to say a very big thank you for all the wonderful work you and your team have put into making my mothers extension come to life. We cannot fault the hard work and dedication of your teams, from the early days of digging to find clay to the final finishing touches. Your workers and those you recommended to us have been highly professional from the apprentices to the master builders.Double Commas

Kind Regards
Siobhan, Nick and Margaret

January 2018

Double CommasAs we embarked upon our first renovation project we were excited though understandably a little apprehensive. Appointing Cox Format we were rewarded with a definitive team lead by an efficient, highly skilled and organised foreman. Daily we were greeted with enthusiasm, reassurance and updates on each stage of the build. Astounded with the level of professionalism provided by the team, their understanding and respect gave us peace of mind and minimum disruption to our home. We couldn’t be more pleased with the completion of our loft conversion. The whole process painless due to the competence of Cox Format. Grade A workmanship. With confidence and zero apprehension we look forward to Phase 2 of our home renovations and welcoming Cox Format back into our home February 2018.Double Commas

Mr & Mrs Te-Ng

May 2017

Double CommasWe decided to appoint Cox Format for our loft conversion after considerable research, which included viewings of their work at other houses and a visit to their offices, which further instilled confidence. Their team are professional, reliable, courteous, and respectful of their customer’s property and their wishes. Peter and Mark were continually visible, always addressed any slight issues we pointed out, and they ensured their contractors also worked to the same standards as their team. We have no hesitation in recommending them and their workmanship.Double Commas


May 2017

Double CommasI had seen lots of development disaster stories on TV, hence I was slightly apprehensive when I decided to do a loft conversion. I obtained several quotes from builders but the minute I spoke with Cox format, I got the sense they were the sort of builders I had been looking for. They were thoroughly professional, specific, clear and transparent. Having viewed one of their recent projects, I proceeded with them for the build. My loft project started exactly on time, and each pre-defined stage proceeded with precision. Work was carried out on a daily basis (managed by James) and the major stages were completed ahead of schedule. Communication was superb, with almost daily updates on progress. Specifically, Mark had an unbelievably swift turnaround time when responding to my emails / texts / calls etc. and this high standard was maintained from start to finish of the project duration…certainly exceeding my expectations. The quality of the work was excellent, and I have absolutely nothing to fault… which is really rare in my case. I would definitely use Cox format again and their number is already first on my list for any future development needs. I would recommended them in a heart beat.Double Commas


May 2017

Double CommasWe used Cox Format for our house refurbishment and the external electrics and lighting for our garden. They had been highly recommended by several neighbours and did not disappoint. All their tradesmen were excellent, fully engaged, and reliable. Their electrician is I believe the best in the business. The few issues that appeared along the way were dealt with swiftly. They are an extremely pleasant company to deal with, and are unlike any other building firm we had come across. True professionals who really care! Peter runs a very tight ship and fully participated in the project and was on site on a very regular basis directing traffic. Mark was in charge of project management and ensured everything ran to plan with no downtime. Drew Newman High Barnet.Double Commas

Mr & Mrs Newman – High Barnet

April 2017

Double CommasI have had a loft conversion carried out recently by Cox Format ltd. Even though I had three additional quotes from other companies which were also competitive I eventually settled on Cox Format. I did this for several reasons.

1.They are an established company with a directly employed labour force.
2.The standard of their work is of the highest quality.
3.Their planning and co-ordination of material deliveries and different trades is first class.
4.They have excellent site supervision on the project from start to finish.
5.Any additional works outside the scope is clearly priced so there are no late surprises on budgets.
6.Perhaps and this is very rare despite promises they stick to their agreed programmes without comprising safety or quality.

In conclusion they are a first class company who do exactly what they say and to programme.Double Commas


April 2017

Double CommasHi Peter,

Just a quick note to say thank you to you and your team for a great job on our loft conversion. We are delighted with the end result and a big thank you to all the tradesmen who helped. Thank you also for the flowers and Champagne you dropped off today. Both were really well received, especially as today is also Sindy’s birthday. Thank you again.Double Commas



February 2017

Double CommasI just wanted to say a big thanks for the loft room. We are so pleased with it. This is the 3rd time now that we have used Cox Format and despite having different builders on each job, your staff have been consistently excellent. Not just the quality of the work itself, but in their conduct and behaviour. Polite, courteous, clean and tidy. And unbelievably fast! Thanks also for being so respectful towards me and my family during such a difficult time, and for resolving issues that arose so promptly.

Thanks again, and kind regards,

Double Commas


January 2017

Double Commas Hi Peter,

I know I have said it to you before, but we really have been very impressed with your company. We have received great service and a fabulous end result.

Thanks very much indeed.

Double Commas


July 2016

Double Commas Hi Mark/Peter,

Many thanks for your work and support during the project – you’ve been fantastic. We’re happy to give any references if you should need them. We look forward to engaging with you again in March/April next year to start the garage conversion.

Double Commas

Drew Newman | Chief Operating Officer
Pyrford International

June 2016

Double Commas Hi Mark,

We are really happy by the way with all your work – the guys have all been great, in particular James who is a god send and has made the process really easy and stress free.

As you know I recommended your work to our neighbour who will be coming to view our property.
Double Commas