Find a Builder you can trust in Welwyn.

Choose from 321 Builders, all rated by people like you.

Over 252 reviews & an average rating of 4.2/5 stars, you'll find the right pro

Choose and shortlist

Use the shortlist button to select up to 4 tradespeople, enter your project details and press send

or

Keen to get on with the job?

Get up to 4 quotes from local Builders near you

View Shortlist
Verified Pro
Welcome to Haas Extension Group, where we take pride in being the premier suppliers, installers, and design consultants of...
Verified Pro

Loft & Build

0 review(s)
Offers services in WELWYN
We can cover all aspects of a loft conversion and extensions. If you require, we can also design the project including dr...
Verified Pro

Primo Contractor

0 review(s)
Offers services in WELWYN
At Primo Contractor Ltd, we are a construction company deeply committed to delivering both domestic and commercial renovat...
Verified ProOver 10 Reviews
Welcome to Home Counties, our team handle projects large and small from residential to commercial. Our Driveway service...

Recent Builder Enquiries

25 Sep

House Extensions

Welwyn Garden City - AL7

Enquiry from: Halima T

Start Date: Immediate

Customer is looking for House Extension quotes. They are unsure of options so would like to discuss. Confirmed interest via SMS//phone Customer lives in Welwyn Garden City area Please call to arrange...

Post a similar request >

17 Aug

Building Work | Porch

Welwyn Garden City - AL7

Enquiry from: Everjoy K

Start Date: Immediate

i would like a quote for an extension. are you the property owner: tenant (with permission) property type: terrace looking for: porch do you have planning permission: yes do you have plans drawn up: n...

Post a similar request >

07 Jun

Insulation | Loft / Roof

Welwyn Garden City - AL7

Enquiry from: Janine H

Start Date: Immediate

loft insulation quote on semi detached house are you the property owner: owner of the property property type: semi detached how many bedrooms do you have: 3-4 do you currently have loft insulationn: y...

Post a similar request >

14 Aug

House Extensions | Single Storey

Welwyn - AL6

Enquiry from: Kate P

Start Date: Less than one month

customer in the welwyn area made an enquiry a couple of projects including single storey house extension.call anytime and arrange an appointment to discuss. below is some details about this project:cu...

Post a similar request >

14 Aug

House Extensions

Welwyn - AL6

Enquiry from: Kate P

Start Date: Less than one month

we would like an extension to be used as a lounge. the area is approx 6m x 4m are you the property owner: owner of the property looking for: single storey extension do you have planning permission: n...

Post a similar request >

17 Jan

Insulation | Cavity Wall

Welwyn Garden City - AL7

Enquiry from: Peter W

Start Date: Immediate

quote for cavity wall insulation to mid terrace 1950's property. note there is a single storey upvc conservatory to rear. are you the property owner: owner of the property property type: terrace how ...

Post a similar request >

06 Jun

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: David B

Start Date: Immediate

full length dormer and full length velux rear ext cost of both about 8metre are you the property owner: owner of the property property type: semi detached are you looking to have stairs: yes what are ...

Post a similar request >

29 May

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: David B

Start Date: Immediate

full length dormer and full length velux rear ext cost of both about 8metre are you the property owner: owner of the property property type: semi detached are you looking to have stairs: yes what are ...

Post a similar request >

23 May

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: David B

Start Date: Immediate

full length dormer and full length velux rear ext cost of both about 8metre are you the property owner: owner of the property property type: semi detached are you looking to have stairs: yes what are ...

Post a similar request >

13 May

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: David B

Start Date: Immediate

full length dormer and full length velux rear ext cost of both about 8metre are you the property owner: owner of the property property type: semi detached are you looking to have stairs: yes what are ...

Post a similar request >

27 Apr

House Extensions

Welwyn Garden City - AL7

Enquiry from: Manuel P

Start Date: Immediate

customer in welwyn garden city areas is looking to do a couple of projects at the moment, and would like quotes for house extension.confirmed interest via email at 27/04/2021 17:59.please call to arra...

Post a similar request >

15 Apr

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: Evi P

Start Date: Immediate

I would like to have a full loft conversation to a bedroom and a bathroom. Curtly the loft is fully boarded.

Post a similar request >

11 Apr

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: Evi P

Start Date: Immediate

looking for a quote and option for loft conversion are you the property owner: owner of the property property type: semi detached what are you looking to convert the space into: bedroom/s are you look...

Post a similar request >

01 Apr

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: Evi P

Start Date: Immediate

looking for a quote and option for loft conversion are you the property owner: owner of the property property type: semi detached what are you looking to convert the space into: bedroom/s are you look...

Post a similar request >

06 Nov

Insulation | CERO Free

Welwyn Garden City - AL7

Enquiry from: Mike C

Start Date: Immediate

5 bedroom detached house potentially needs external wall insulated.

Post a similar request >

01 Aug

Conversion | Garage

Welwyn - AL6

Enquiry from: Natasha C

Start Date: Immediate

treatment room - plumbing, sink and toilet, door and window fitting, flooring and walls. are you the property owner: relative of owner do you have a: single garage what will the space be used for: ot...

Post a similar request >

06 Jul

Building work | General

Welwyn - AL6

Enquiry from: Anita K

Start Date: Immediate

1. Maintenacne of rainwater goods which includes replacement of downpipe, provision of downpipe bracket and securing lose stop ends 2. Re-ponting of brick joints 3. strenthening works to the roof tr...

Post a similar request >

22 May

Conversion | Loft

Welwyn Garden City - AL7

Enquiry from: Paul L

Start Date: Immediate

customer visited the myloftconversionprices.co.uk site and submitted an enquiry. property type: detached, property owner: owner, looking to convert into: living space, work description: conversion of...

Post a similar request >

03 May

House Extensions

Welwyn - AL6

Enquiry from: Siva G

Start Date: Immediate

are you the property owner: owner have you considered getting your windows replaced to match a new conservatory: no other forms: kitchen design & installation, house extension agreed to receive quote...

Post a similar request >

04 Jul

Building work | General

Welwyn Garden City - AL7

Enquiry from: Steven E

Start Date: Immediate

I'm buyinga Euramax Edwardian conservatory 3m deep x 3.8m wide. The ground work and wall will already be done, I just need a professional to erect it Are you the property owner: Tenant (with permiss...

Post a similar request >

How much do Builder services cost?

How much do Builders cost? Prices for Builders in 2025 can fluctuate relying on the sort of work that you need to have carried out in your residence.

Are you planning to erect a new house or structure? If yes, then you’d probably want to know just how much it’ll take to get the project over the line to help you set a budget and start to plan. Building a new house is requires huge financial investment and as a result, there’s the need to carry out your due diligence before you proceed. In this post, we’re going to give you an insight into the prices charged by builders to erect a new home or structure.

First and foremost, like every other home project, the price charged by builders to construct a new house or structure depends on a wide range of factors. These factors include the size, location, accessibility as well as qualifications of the builders you wish to employ just to mention a few. For instance, you’d expect the cost of building two-storey in London to be a lot more expensive than the price of a one-story building in Scotland. However, we’ll try our best to give you an idea of the price range you can expect to incur to complete your project.
In general, a builder will charge within the range of £10 to about £15 per hour on the average. For small building projects which includes wall and foundations repairs, a builder will typically charge about £11 per hour. However, the price charge will depend on the extent of the job due to the fact that simple tasks such as repointing only costs about £10 per hour, while laying new foundations can cost up to £15 per hour.

The table shows the types of work that Builders typically do and the average cost range of these tasks. Some tasks take longer to finish than others so prices do fluctuate by job.

View our Builder cost guide View our Builder advice

The average price
of a Builder in Welwyn is:

£25,829

Builder job Builder cost in 2025
Garage conversion in Welwyn £9,750-£18,450
Loft conversion in Welwyn £39,375-£59,375
House extensions in Welwyn £34,250-£72,000
Loft insulation in Welwyn £450-£690
Upvc or wood porch in Welwyn £2,625-£4,025
Barn conversions in Welwyn £112,500-£172,500
Basement renovation in Welwyn £30,000-£46,000
Bedroom fitting in Welwyn £1,500-£2,300
Bricklayers in Welwyn £300-£460
Cavity wall insulation in Welwyn £400-£820
Commercial new builds in Welwyn £105,000-£161,000
Conservatory base in Welwyn £675-£1,035
Building maintenance in Welwyn £2,250-£3,450
Building insurance works in Welwyn £2,250-£3,450
Pebble dashed walls in Welwyn £2,000-£9,200
Plasterboard dry lining in Welwyn £638-£978
Residential new builds in Welwyn £105,000-£161,000
Restoration and refurbishment in Welwyn £37,500-£57,500
Roof insulation in Welwyn £7,500-£11,500
Underpinning in Welwyn £2,250-£3,450
Wall cladding in Welwyn £1,125-£1,725
Wall rendering in Welwyn £3,750-£5,750
Demolition in Welwyn £2,440-£3,660
Roof room in Welwyn £15,000-£23,000
Shop refurbishment in Welwyn £3,750-£5,750
Single storey house extension in Welwyn £21,600-£37,400
Soundproofing in Welwyn £900-£1,380
Driveway repair in Welwyn £607-£51,140
Garden room in Welwyn £6,400-£9,600
External wall insulation in Welwyn £6,000-£15,000

Related Builder searches in Welwyn

Builder FAQs

Are barn conversions VAT exempt?

If you’ve converted a non-residential barn into a home, you might be able to reclaim some of the VAT that you’ve paid for your project. This includes money spent on:

• Construction materials

• Flooring

• Light fittings

• Kitchen units and worktops

• Electrical, heating and plumbing materials

To reclaim your VAT from HMRC, make sure you request and keep all of your invoices. You’ll also need proof of planning permission and evidence of completion. You should then submit your claim with all relevant paperwork within three months of receiving your completion certificate. You’re only allowed to submit one claim, so you’ll need to make sure you get it right first time.

Will my patio need a lot of maintenance?

Patios do not require lots of maintenance. They will only need occasional cleaning to make sure that the material keeps its original appearance. It's always best to clean your patio with a pressure washer and occasionally tap each slab or brick just to check the sand underneath hasn't washed away.

Will my extension be expensive?

It depends on the size and type of extension. Small porches or flat roof extensions are very reasonably priced. More substantial two storey extensions can be expensive. In general, the price is roughly proportional to the amount of space you add to your home.

How to renovate a house?

As with every home development project, a home makeover comes with heaps of preparation and, hard work, but it is a remarkable way to breathe new life into an old home.

RESEARCH PERIOD FEATURES AND SAFEGUARD THEM

Get to know your household better, the time it was constructed in, and the kind of individuals who would have lived there. The greatest tactic is to repair current structures, make the house dry and safe.

CHECK FOR RENOVATION RESTRICTIONS BEFORE YOU START

There are certain restrictions that don’t allow you to remodel your house after a certain extent, it should be made clear to you when you purchase the property but if you are unsure about the regulations you should check them up, as it is a criminal offence to carry out unauthorised work to a listed home. Restrictions in Conservation Areas generally affect only the exterior of the property as the intention is to ‘preserve or enhance the character or appearance’ of an area, but the right to develop your house will be affected. This means the kind of work that you could have easily completed in a different location may need certain planning and even permissions to complete in your area.

CREATE A DESIGN FOR YOUR HOUSE RENOVATION

It is very important that you take your time to perfect the design. This will help to ensure that the finished work is in tune with your needs. You will also need to figure it out how the changes might play with the original building.

FIND THE BEST CONTRACTORS FOR YOUR RENOVATION

If you are planning on managing the renovation project yourself, it is advisable to ask from friends or family who have renovated their house before and have undergone a similar experience. They can help you find the right architect and builder. Or else, you can always opt for a project manager.

does a kitchen extension add value to your house?

If you’re planning to add a kitchen extension to your property or perhaps you’re simply looking for ways to increase the value of your property, this is one of the common questions that usually pops up. A simple answer to this question is yes, a kitchen extension will add value to your house. With a kitchen being one of the most frequently used room in a house, adding an extra space to the commonly used room can only increase the value of the entire property. However, to determine the value added by such an extension, there’s a need to calculate the cost of setting one up first.

Kitchen extension costs are greatly influenced by a wide range of variables such as the size, type of the extension and specifications, your location, professional fees, materials used and more. Overall, the type of the extension you opt for will play the most significant role in the determination of your kitchen extension cost. Here, we’ll be looking at a single storey kitchen extension.

For a single storey kitchen extension, you can expect your home’s market value to increase within the range of 5 percent to about 10 percent. When trying to calculate the cost of kitchen extension, it’s crucial to take into account how much value it’ll add to your home so as to make sure that the amount expended will not outweigh the expected value to be added by the project.

For a more accurate idea, there’s the need to consult local estate agents. However, for a much needed guideline, single storey kitchen extensions are usually able to add about 5 to 10 percent to a home’s value, while double storey extension should be up to 20 percent. But as stated earlier, this will depend on several variables.

how much does it cost to renovate a house?

Do you want to inject a new lease of life into your home or property, or transform it into a more modern style that better suits your taste? Or perhaps you’re only looking to add more value to your property to enable you sell for a profit in the nearest future. Regardless of your purpose, determining the cost of your home renovation can be incredibly difficult. However, you can still obtain a reasonable budget for the project with proper planning as well as preparation. It’s almost impossible to get an exact figure for any home renovation cost, however, this article aims to give you a good idea of cost range to enable you make informed decisions.

The cost of renovating a house can vary significantly depending on a wide range of factors. Some costs are fixed while others may vary greatly. As a result, if you want to have a more exact figure, you’ll have to call in a professional beforehand to give you an idea of how much they’ll charge. Below are some of the most significant costs you’ll most likely face during property renovation.

✓ Administrative cost. Asides from material and labour, the administrative costs is another important cost you’ll need to factor in. The first thing here is usually insurance, this is because all regular building insurance policies does not cover large scale renovation projects. So if what you’re planning is a huge structural change to your property, then it’s more likely that it won’t be covered by your buildings insurance policy. In this event, you’ll have to take out a specialist renovation insurance.

✓ Planning permission and property renovation. This is another potential cost you’ll have to factor in. Submitting a planning application in the UK usually ranges between £200 to £250.

✓ Adding an extension. Generally, a 4m by 5m extension would cost within the range of £30,000 to £40,000.

what is a garden room?

Over the years, garden rooms have gradually become a popular choice amongst homeowners as a cost effective way of expanding living space within a home or property. A garden room is basically a living space and a type of pavilion building made from wood that’s well insulated, double glazed as well as electrically wired. It’s however a building which is subsidiary to the main one, built with the purpose of creating an extra functional space within the property. These garden outbuildings are very functional and can be used as a garden studio, office, salon and much more. They can also be incorporated for recreational purposes for evening relaxations, family and friends get-together, lounge or even spa. Other possible uses of a garden room include gyms, pool houses, playrooms, dens, home cinemas and game rooms.

Garden rooms are functional living spaces that are usable throughout the year. And with the rate at which their popularity is growing, you’ll find some companies offering cheap and low quality alternatives featuring shed like construction and felt roof. Garden rooms, on the other hand, are a valuable investment with superior designs and top notch build. They’re constructed in a very similar way to houses with timber frames. Furthermore, they are fully insulated and can also include the normal building solutions such as heating and running water, electricity and many more depending on the requirements of the home or property owner. With the durability of garden rooms being a major objective, they’re typically clad in natural solid timber like Cedar, Larch or Acacia. Materials such as EPDM rubber or cedar shingles are normally used for the roof covering. What’s more? They usually have large expanses of glazing and glazed doors fitted.

How much does external solid wall insulation cost?

Before the commencement of any project, it’s always best to get an estimation of the cost. However, determining the cost of an external solid wall insulation is not the easiest of tasks as it relies on varying components such as the insulation materials to be used, labour cost and installation as well as the type of decorative finish to be incorporated. And depending on your choice of insulation material, some may need some adhesives while others may require some fixings which also contributes to the differences in price. As a result, the determination of the material cost alone can be tricky and even more so when various materials cover varying areas.

With that in mind, the cost of external solid wall insulation generally ranges between £80 to £100 per square metre2. As a result, a small flat can cost from £6000 to £9000 whereas a large detached house can have a price ranging between £21000 to £23000. To earn back your investment in terms of energy bill savings can take a couple of years, but it’s surely worth the try as there are several other benefits associated with installing an external solid wall insulation system. What’s more? Another huge factor that can influence the cost of your system is also the amount of work that’s required, how easy it is to be accessed by the installers and lots more

If you’re looking to cut down on the cost of your external solid wall insulation, then the best time for an installation might just be when you’re having another decorating or building project done such as fitting a new roof, window painting, installation of solar PV panels and more. This way, you’ll be able to spread the cost and have a greater value for each penny expended.

Builder help and advice

How it works

Tell us about your Builder project

Answer a few quick questions to help us match you with the right Builder

Get up to 4 free quotes

Receive no-obligation quotes from 4 Builders working in Welwyn.

Pick the right pro for you

Compare prices, customer reviews and services, and hire the right Builder.

Are you a Builder in Welwyn?

View our open Builder jobs near you

Join today
View Shortlist