Extension builders in Swindon
Read what our customers have to say
The Quality of our workmanship: When the front of my mother-in-law Jean’s home suddenly collapsed, it was a deeply distressing moment for our whole family. The damage was dramatic and unsettling — not just structurally, but emotionally too. Jean had lived in that home for over 59 years, and the idea of losing it was overwhelming.
Our professionalism and communication: JohnPaul brought the kind of expertise that immediately instils confidence. His knowledge, attention to detail, and steady leadership were evident from day one. He took the time to walk us through the plan, and his team executed it flawlessly.
Our problem solving activities: The entire crew were polite, punctual, and incredibly respectful of Jean’s space. The work was completed on time and within budget — and most impressively, Jean was able to remain living in her home throughout. The process was so well-managed and unobtrusive that it never felt like a construction site. It felt like a team restoring something precious.
Our reliability and efficiency: The final result is stunning. The house is not only structurally sound but beautifully rebuilt, with every detail thoughtfully finished. Jean is absolutely delighted.
Your overall Satisfaction: GWBS didn’t just rebuild a home. They restored peace of mind, and showed what true professionalism and empathy look like. We would recommend them without hesitation to anyone seeking not just skilled builders, but a team who genuinely care.
The Quality of our workmanship: I recently had the pleasure of working with GWBS on my home renovation project, and I couldn’t be more thrilled with the results. From the very beginning, their team was professional, attentive, and genuinely passionate about bringing my vision to life.
They took the time to understand my needs and provided valuable insights that enhanced the overall design.
The craftsmanship is outstanding; every detail was meticulously executed, and the quality of materials used is top-notch.
Moreover, the entire crew was friendly and respectful, creating a positive atmosphere on-site.
Our professionalism and communication: Communication was seamless throughout the process, making it easy to stay updated on progress and timelines.
Our problem solving activities: Any problems were small ones and were sorted very easily. We had a WhatsApp group so that everyone knew what was happening. It was a large project and the team became friends. Even making ME a cup of tea.
Our reliability and efficiency: The team were extremely reliable, always turning up at 8am on the dot. I had no problem trusting them with my door key, as I am a disabled lady who sometimes struggles to answer the door in time. I really appreciate their commitment to meeting deadlines without compromising on quality.
Your overall Satisfaction: I am delighted with my new space and highly recommend GWBS to anyone looking for a reliable and skilled builder. Their dedication to customer satisfaction truly sets them apart!
The Quality of our workmanship: The inside of a building is experienced by the few who live there or visit. The outside of a building effects everyone who passes by. People have to suffer it or enjoy it for decades. This work was to the facades of two houses in a terrace which is more than two hundred years old. The quality speaks for itself. Everyone who passes stops to say what a wonderful transformation it is. It is a truly superb job.
Our professionalism and communication: From the day we first met on site, through to completion and beyond, communication has been first rate. The team were lovely to have around and nothing was too much trouble for them. No-one likes to have a customer looking over their shoulder, but when I wanted to be shown what they were doing or to see how it was going, I was always welcomed onto the scaffolding.
Our problem solving activities: This job was one massive problem, right from the start. In addition to Great Western Building Services, I discussed the job with eight other builders. Some who I know well and some who came highly recommended. Some did not want to get involved. Some wanted to demolish everything and start again using modern techniques, and some just stopped responding or didn’t show up. There were also three structural engineers who did not want to get involved. From the beginning, JP was clear how he would approach the job.
Our reliability and efficiency: In project management there is a principle of “Triple Constraints”. Of the three constraints of budget, timescale, and quality – only two can be achieved – one of them has to be compromised. This project was on budget, on time and the quality has to be seen to be believed. I have never seen this happen before. Two of the other builders I approached, have made a point of getting in touch with me to say what a superb job it is.
Your overall Satisfaction: I’m delighted.
This job needs before and after photographs to demonstrate how wonderful it is.
Would definitely use GWBS again and would very happily recommend.
The Quality of our workmanship: The standard of quality and workmanship throughout the build was outstanding. When the build was complete, there was little or no snagging to be carried out as everything was perfected as the team progressed.
Our professionalism and communication: John Paul and his team communicated well from Start to finish. Always ready to answer any questions we had and to give us peace of mind with any concerns. Work progressed well despite some atrocious weather conditions and despite Covid restrictions
Our problem solving activities: As expected, some problematic issues arose throughout the works. Such as enormous lintels in complex areas. Such issues were dealt with efficiency and professionalism.
Our reliability and efficiency: The project was completed on time and we were consulted every step of the way. The team were professional and efficient throughout the build
Your overall Satisfaction: We would certainly recommend Great Western Building Services for any Building and plumbing related work. From initial contact and quoting through to moving in, what could be a stressful and difficult experience, turned out to be an exciting and satisfying one. Not only would we recommend GWBS, we have on several occasions.
The Quality of our workmanship: The quality of the workmanship was second to none. John-Paul and his team kept us updated at every stage of the project and was extremely helpful in shaping our ideas. We wanted to build a solid wood shelf to house our two sinks but I wanted something authentic; the team supported our idea by advising us how we could achieve this and where to find the best wood to do this. We now have a stand out shelf that spans the width of our bathroom which everyone comments on as the wood was from a timber yard and you can see the tree rings – it look so beautiful and I could not be happier with the outcome.
Our professionalism and communication: Excellent. Our bathroom was not a refit it was a complete renovation including taking the ceiling down, taking off all the existing tiles and bringing it back to the brick and pulling the floor up. It was massive and as you can imagine quite an intrusive job as it was the family bathroom but John-Paul and his team made the process as easy as they could be keeping to the project plan and working efficiently throughout.
Our problem solving activities: The main reason for refurbishing our bathroom was to solve an age of problem of mould which came from having 3 external walls. In the summer it was fine but the winter was a nightmare and the mould build up was terrible. We advised John-Paul and his team of what we were trying to do which was to retrospectively insulate the bathroom, they showed us how we could achieve this and the best products to use. We know not only have a beautiful bathroom but one that is warm and mould free!
Our reliability and efficiency: Excellent – they started and finished pretty much when they said they would. I can only recall one day when a there was no one on site and that was due to the team getting stuck on the motorway following a tyre blow out.
Your overall Satisfaction: 10/10. John-Paul and his team are a dream to work with. They don’t just build then advise, problem solve and guide throughout. Very impressed with the service provided and would not hesitate to recommend.
I have worked with JP for about 15 years, starting with Donovan Construction working on two projects for local schools, and then with Great Western Building Services, working on a number of domestic projects.
I have found JP to be a conscientious, diligent, highly competent and skilled building contractor. He is pro-active and client focussed, always looking for solutions to ensure the finished result is a success.
He takes pride in his work which feeds through to his employees and the ethos of the company. I have no hesitation in providing this reference and hope to be working with him for future projects.
With J.P and Carly you will be working with people who have good communication skills, they were always very accessible, helpful, nothing was too much trouble and always mindful that we were happy with how things were progressing.
Communication with builders.
All the trades involved with the build were always polite, thoughtful, considerate, tidy, punctual and went beyond what was asked of them.
Quality of work
The quality of the work was exceptional throughout. The site was always left tidy and secure and safe for us to always access our home.
Overall
We feel the whole experience has been worth the money they have created for us an amazing home, we would recommend GWBS to anyone, you will be in safe competent, professional caring hands, they will give you home to be proud of.
Since working together J.P and Carly we have become very good friends.
Work carried out:
In October 2022 we jointly purchased a 5-bedroom house with the prospect of adding a 6th bedroom and developing the property to make a dwelling for our two families to live together, but with separate living quarters. The house was in a poor condition with nothing having been developed/improved for some decades.
The plan was to build a large single-story extension across the back of the house providing two living room/kitchen/diners and to convert the garage and utility area into a bedroom and ensuite bathroom.
Communication with builders.
From day one the communication with JP was excellent. The quotation document was thorough and detailed in the extreme and gave us great confidence that we had made the right choice out of the quotes we had sought.
Throughout the whole 6 month process we were kept well informed, and since we were in temporary accommodation nearby, we were able to visit the site regularly. We got to know JP and the whole team really well and were always welcomed on site.
Where issues arose or choices needed to be made JP helped us with decisions and was always determined to help us achieve the best balance between quality and cost.
JP was also very thorough in communicating with the neighbours who were inevitably affected by a 6-month building project.
Quality of work
At every stage of the build the quality of the workmanship was excellent. This has been confirmed by friends who know far more about building than we do and who, without exception, make very positive comments when they visit. JP is somewhat of a perfectionist, a very desirable characteristic for a builder!! We can say that the result is pretty much exactly what we had hoped for.
Tidiness of site
By its very nature much of the work created a great deal of rubble and required a never-ending supply of skips. The team clearly did their utmost to keep all this to a minimum and it was particularly noticeable that on a Friday evening they cleared and cleaned up the frontage of the house to leave things looking as tidy as possible for the weekend.
Value for money
As I hinted earlier, JP is not one to take short cuts to provide a cheaper option. In our various discussions we were confident that we could absolutely rely on him to provide us with an excellent result at the most appropriate price.
Overall
Six months in temporary accommodation whilst waiting for a build to be completed is inevitably unsettling and stressful. JP did everything he could to make the process as stress free as possible – on a couple of occasions he called in on us just to see how we were doing! I am hoping this is the last major building project we will experience, but if anything crops up there is absolutely no doubt about who we will get to do the work!

We have nothing but the highest praise for Mr. Donovan and his great team.
We had previously selected Great Western Building Services for a small extension to our lounge and hall, which greatly improved our living space. They were not the cheapest, but we were impressed with the quality and detail in their quotation, which gave us great confidence, and we were not disappointed.
When it came to our more recent, and much more ambitious project, we had absolutely no hesitation in inviting GWBS to tender.
The scope of the project was a to be attached to one corner of our bungalow, plus extensive landscaping to the rear of the property. The design of the orangery featured a centrally-located roof lantern in the otherwise tiled sloping roof, and a steel frame, two-tiered to support the roof; steel being required due to the minimal walls and very large windows including full-width bi-fold doors.
The quality of workmanship throughout was outstanding, as was the impressive attention to detail. The site was always kept tidy, the GWBS team were always polite and considerate, and we were always kept informed of plans. Indeed, while we were away on holiday we were even sent photos and a video of the roof lantern being lifted into place by a special crane.
The work was completed on time, despite the challenging heat, which necessitated some unplanned non-working days, and some delays from third parties. It was also completed on budget, allowing for one or two agreed minor changes.
We would have absolutely no hesitation in recommending GWBS.


Very easy and quick to respond to queries. Helpful with suggestions for finishing materials etc.
JP was always very approachable and responsive. He demonstrated different building material options when we had to make a choice. On one occasion he rushed out at 9pm to solve a challenge before kitchen worktops arrived at 9am the next day.
The outdoor crew – Craig, Bill, Lee (and others) were really friendly and polite. They went the extra mile to be helpful and tidied up well at the end of each day.
Excellent quality of workmanship. The exterior build is fantastic – the front porch/hall is impressive, and the rear extension brickwork really matches our existing building. The finish of the patio with its retaining wall is great. The care given to the finish – plastering, windows, doors and kitchen fitting has given us a “show house” feel.
GWBS kept the site as tidy as possible during each phase of the build. Skips were regularly emptied. Materials were kept in prearranged places. The garden was returned to original state as much as possible. When the back house wall was removed the team carefully boarded the gap and re-plumbed the sink further back enabling us to continue living in the house whilst the building was completed.
Not the cheapest quote but by no means the most expensive either. We chose GWBS over other builders as we felt we could work easily with J-P, he was keen to ensure that we ended up with a high-quality extension finished in the style of our choosing. J-P is a rare builder – one who listens to concerns, explains what is going on and genuinely tries to give the best results for the agreed budget. J-P sourced a competitive quote for our outsize windows and patio doors. When we made minor changes, we always felt that J-P did not exploit the alteration but either folded it into his plans or quoted a fair price.
We would be very happy to use GWBS again and recommend them to friends and relations considering building work.
JP and his amazing team have created a wonderful extra “living space” for us.
Thanks a bunch JP.
The plastering finish was perfect and electrics were just as we wanted them to be.
Cleaned all the rubbish away.
I would definitely recommend them.
Satisfied customer.
Highly recommended.
His brickies turned up on the agreed date and time, did a good job, were very polite, tidy and considerate, working late to finish the job and cleaning up afterwards.
Jason Walker project managed the build and trades, from start to finish including fitting the kitchen and flooring. He and his team were very easy to work with; helpful, friendly, trustworthy and very hard working.
All of the team were very communicative, quick to find a positive solution for anything that came up as the work progressed, and willing to go the extra mile to ensure the best possible outcome.
We are very pleased with our new extension.
As with all building projects we
had one or two problems along the way but were resolved by the team to my satisfaction.
They were helpful when I wanted to have some extra work done outside.
The build was completed at a good speed, the team were open to last minute changes and/or additions with minimal issues and pricing was very competitive.
We love the finish and quality of work carried out and we would recommend GWBS for all building works…
If you need to see any pics of their work then please get in touch, thanks Mr & Mrs Collins, Hilmarton.
The team are hard working, diligent and professional with a collaborative approach at every stage and this has ensured we have remained on target with timeline, budget and aspirations for the build.
Also very pleased with their continuous drive to deliver a quality build whilst also being considerate of the “fluffy stuff” such as being very personable and keeping the working site orderly.
Happy to recommend.
GWBS were able to recommend under flooring to level out the floor and protect my Porcelain tiles from snapping (especially if there was further movement of the floor) They then designed a layout of the tiles so that they looked perfectly straight and any joins to do this were hidden under the door way.
They were polite, professional and tidy. They arrived when they said they would and the job was completed within the time frame given.
I would highly recommend GWBS as you certainly get what you pay for.
Get in touch with professional extension builders in Swindon. Contact Great Western Building Services Ltd on
07860 247 430 or 01793 764 139