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myTimber Frame Extension Cost
At a Glance
- The average cost for a timber extension is £36,000.
- It will take roughly 6 to 12 weeks to complete.
- A breakdown of pricing information for different types of timber extension.
- How long the job will take, and a general overview of what the job entails.
- Whether you need planning permission.
- How to find and hire tradespeople.
Want to discover the cost of building a timber frame extension?
This complete guide covers all you need to know about timber frame extension costs, including the cost of an oak frame extension, lean to wooden extension prices and more!
We also have plenty of builders ready to give you a quote for building a timber frame extension.
Need more cost information? Check out the guide below...
£36,000
Table of Contents
- How Much Does a Timber Frame Extension Cost?
- Timber Framed Extension Prices
- Labour Costs and Timescales
- What Affects the Cost of a Timber Frame Extension?
- What's Involved with Building a Timber Frame Extension?
- Who Can Plan my Timber Frame Extension?
- DIY Timber Frame Extension
- Timber-Framed Extensions VS Brick Extensions
- Planning Permission and Building Regulations
- What Fire Protection Regulations Need to be Followed?
- Different Types of Timber Frame Extension
- Hiring a Timber Frame Extension Specialist Checklist
- FAQs
How Much Does a Timber Frame Extension Cost?
On average in the UK, the cost of planning and constructing a timber-framed extension ranges between £1,600 and £2,700 per square metre. However, it is essential to recognise that many factors will contribute to determining the overall cost.
These cost-affecting factors include the finish of your extension, the size and complexity of the extension and the quality of the materials used to construct your extension.
Many advantages make timber-framed extensions so popular amongst homeowners, the first being the overall construction time. Compared to using bricks, which is commonly the default method of building home extensions, timber frame extensions are often much quicker to construct - they're usually cheaper than the cost of a brick extension, too.
Timber frame extensions are also less likely to be affected by the weather, which means that you will be able to get your build to a weather-tight phase much quicker than alternative methods of construction.
This process saves you time and will likely be much cheaper than alternative building methods, as your contractor's hourly or daily labour rates will be reduced.
We're thinking of using a timber frame kit for our extension and leaving some of the wood exposed inside. However, I'm worried about fire safety as it'll house part of our kitchen. Are there any building regs etc to be aware of or things we should do to make it fire-safe?
"As long as you're not silly and put the hob directly next to the exposed timber you will be OK, also the plasterboard should be the pink fire resistant ones which will help, I also think every kitchen should have a fire blanket near and a small foam extinguisher under the sink."
Timber Framed Extension Prices
There are many cost-affecting factors to consider when calculating the overall price of building a timber frame extension. Please note that the costs in this table are estimated and should be used as a rough guide only.
| Extension Size | Timber Used | Price Per m² | Cost |
|---|---|---|---|
| 15m² Single Storey Extension | Pine Timber | £1,600 – £2,100 | £24,000 – £31,500 |
| 30m² Single Storey Extension | Pine Timber | £1,600 – £2,100 | £48,000 – £63,000 |
| 15m² Single Storey Extension | Maple Timber | £1,800 – £2,300 | £27,000 – £34,500 |
| 30m² Single Storey Extension | Maple Timber | £1,600 – £2,000 | £48,000 – £60,000 |
| 15m² Single Storey Extension | White Oak Timber | £2,000 – £2,500 | £30,000 – £37,500 |
| 30m² Single Storey Extension | White Oak Timber | £2,000 – £2,500 | £60,000 – £75,000 |
| 15m² Single Storey Extension | Red Oak Timber | £2,200 – £2,700 | £33,000 – £40,500 |
| 30m² Single Storey Extension | Red Oak Timber | £2,200 – £2,700 | £66,000 – £81,000 |
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Labour Costs and Timescales
To build and complete a timber-framed extension, you’ll need to hire various labourers.
Timescales for a timber frame extension are never accurate, due to numerous unforeseen circumstances that can occur, but here's a rough estimate to base your budget on:
- Small extensions (15m²) can take between 6 and 8 weeks
- Medium extensions (30m²) will take 10 to 12 weeks
- Large extensions (60m²) can take 12 to 14 weeks or longer
The table below will give you an idea of how much you can expect to pay different tradespeople.
| Type of Labourer | Avg. Cost Per Day |
|---|---|
| Builder | £160 – £340 |
| Plumber | £150 – £280 |
| Joiner | £140 – £210 |
| Electrician | £150 – £400 |
| Plasterer | £120 – £200 |
| Roofer | £160 – £280 |
| Painter and Decorator | £120 – £230 |
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What Affects the Cost of a Timber Frame Extension?
When planning your new timber frame extension, you should consider the desired look and finish you wish to have. Some of the most common are red oak, white oak, cedar and pine. The species of wood that you use will determine the overall quality and cost of your timber frame extension.
It's best to talk through your options with your extension specialist, as the lowest-priced timber might not always be the best choice. Lower-priced timbers can sometimes lose their structural support over time, making them unsuitable for a timber extension.
Another cost-affecting factor that you will need to consider when planning your new extension is what type of exterior finish you would like. Some of the most common exterior finishes used with timber-framed extensions include rendered boards, red brickwork, brick slips, metal cladding and timber cladding.
Each of these materials will vary in price, adding to the overall cost of your project. They will also determine the final aesthetic result and quality of your extension.
What's Involved with Building a Timber Frame Extension?
Here are the steps you'll need to take during your timber frame extension project:
Find Reputable Contractors
Start by comparing contractors in your local area and reviewing their previous work. Once you've chosen your trader, your building specialist will visit you to assess the scale and complexity of your project.
You will also need to source a qualified architect or designer to sketch up the first plans to get an idea of how your finished extension will look.
Get Building Consent and Check Planning Permission Requirements
After you have contacted a reliable architect to construct the initial plans, you will need to obtain the correct building consent from your local authorities.
If your extension exceeds the criteria set by your local authority, then you will need to apply for planning permission before commencing any construction work.
Choose Your Materials
You should discuss with the building firm that you have chosen the different options that are available to you when creating your new timber frame extension. Ask about each material's advantages and disadvantages and how this would affect your final project cost.
Decide Extension Size
Think about how many storeys your extension will cover. Remember that this is also going to increase your final project cost significantly. You and your contractor should talk about the exterior finish you are aiming to achieve and what material would be most suitable for your project.
External Building
Once you have all of the plans and regulations in place, the physical construction work can commence. Your team of specialist contractors will begin working on the ground of your property to develop a structural foundation on which your extension will sit.
Generally, the foundations or as they are commonly referred to as footings, are made out of concrete or stone, to give the timber frame of the building support. Depending on the contractor you hire, your timber frame extension can either be constructed on-site, at your property or off-site in a workshop.
The skeleton or frame of the extension can generally be built using soft or hardwood panels, which increases the ease and efficiency of the construction time.
Your timber frame will be assembled by the skilled professionals you have hired, along with any insulating timber boards or panels. The main advantage of using timber to construct any building work is the efficiency and speed of the construction phase. It is much easier for your builders to progress your build to a water-tight, weatherproof state as opposed to using alternative building methods.
Internal Finishing
Once the framework of your extension is securely in place and water-tight, work can commence on the interior and exterior proportions of your build. This is where any windows, doors, cavities and exterior finishes can be installed along with roofing and roof guttering systems.
If you have agreed to, then your building firm will begin working on the interior of your extension, such as the electrical wiring, plastering and decorating.
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Who Can Plan my Timber Frame Extension?
It is important to recognise that in the UK, there is currently no law stating that you must have an architect to submit plans for your new extension. However, we always recommend the best possible way for you to make the process run as smoothly as possible and achieve the best quality results.
We will always suggest that whenever you are planning on carrying out extensive building work on your property, you seek the advice and services of skilled professionals who are experienced in this area.
Hiring a qualified architect is by far the best way to achieve a detailed plan and diagram of how you envision your new extension to be. An architect will cover all elements of your build and will be able to advise you on the best possible recommendation and solutions that will benefit your case.
Many architects will often charge a percentage of the final cost of your extension. Usually, this percentage is between 8% to 15%. Consider that if your total project cost is £50,000, your architect may charge up to £7,500 for their design service.
Alternatively, there are trading companies that offer similar services for homeowners who are planning a property extension but might not know where to start. These companies provide simple design services, either by CAD (computer-aided design) drawings or 3D models, specialised in the construction of home extensions.
Often, design firms will offer a variety of packages, from partial plan designs to full planning of your extension. Depending on the level of service you require, you may end up paying between £100 and £150 per hour for a CAD designer.
I'm building a timber frame extension and need to confirm the width and depth of the footing. A lot of people are saying 450 wide and 1 metre deep. Is this excessive for a timber build?
"Any extension should be going through building regs. This is something that is always checked by the building inspector."
DIY Timber Frame Extension
Building a timber frame extension is an extensive renovation project that is best left to the professionals.
However, there are certain aspects of the project that you can do yourself to help move things along if you feel competent. One advantage of working with timber is that it is much easier and lighter to assemble compared to other methods of building.
You may find that you can construct the timber framework yourself, either on-site or off-site, and progress to a stable, water-tight build phase. This will save you both time and money as you will only require the assistance and service of a construction firm for part of the build.
However, if the structural work of your extension is not correctly assembled and stable, your property will be at risk. To ensure that you receive the best quality finish, you should always consider speaking to an experienced professional before attempting to carry out the work yourself.
Building any kind of home extension is a huge task, requiring professional skill and materials. Not only that, but the use of power tools can be exceptionally hazardous if used by someone inexperienced or unskilled.
Some of the most common disasters associated with self-builds are issues with the finish, quality and functionality of the final result. Confident DIY-ers will believe that they do not necessarily need to pay for a professional tradesperson's service, attempting to carry out the work themselves.
More often than not, they will face issues when trying to follow the architect's designs and plans. Following construction plans and working alongside qualified designers requires a lot of patience, experience and skill, which the average DIY-er often struggles with. The result is a project that lacks a quality finish and potentially breaches building regulations.
Timber-Framed Extensions VS Brick Extensions
Let's take a look at the pros and cons of choosing a timber framed extension versus a brick extension.
Timber-Framed Extensions
Using the timber frame method to build your new home extension will significantly reduce the labour charges of your traders because the process is much quicker to complete.
Many manufacturers will guarantee that any of their construction timber has a lifespan of up to 40 years. However, you need to consider that wood is an organic material and susceptible to rot and breakage.
Pros
- ✔ Faster and more efficient to construct compared to brick extensions
- ✔ Lower labour costs compared to brick extensions, as the build time is shorter
Cons
- ✖ Timber frame extensions have an average lifespan of 40 years, significantly shorter than brick lifespans
- ✖ As timber is a natural material, it can be susceptible to rot, moisture damage, and invasive pests if not maintained
Brick Extensions
Unlike timber builds, brick and blockwork extensions generally take longer to get to a water-tight phase, as weather will often interfere with the construction.
The weather conditions need to be right when working with bricks and blockwork, or the cement will not set correctly, resulting in a weak and unstable finish.
Many construction companies and local tradespeople will charge an hourly or daily rate for their services. The longer your project takes to construct, the higher these fees are going to be.
Pros
- ✔ Superior durability compared to timber extensions, lasting for 150+ years
- ✔ Low-maintenance once built
- ✔ More traditional appearance, blending seamlessly with UK houses
Cons
- ✖ Dependent on weather conditions to build, which can make build times much longer and more costly compared to timber constructions
- ✖ Labour costs are higher
I'm looking to build a single-storey extension (timber frame with a flat roof). Can anyone advise what depth footing I will need? The dimensions are 4mx5m, but I'm just costing it all up at the moment.
"The footings will still need to be 1000mm deep at a minimum, the building inspector will look at 1000mm deep and determine whether you need to go deeper."
Planning Permission and Building Regulations
Many people often wonder whether they will require planning permission for their timber-framed extension. The answer is, possibly.
The case will depend on the particular extension plans and design. Your local authority will have guidelines and regulations that need to be followed at all costs.
If your project requires planning permission and you begin the construction without obtaining consent, you will be in breach of your local authorities building regulations. The consequences of building without planning permission may risk your building needing to be demolished.
However, not all projects require planning permission. Usually, a build that does not exceed 4 metres in height and is under half of your property's width does not require consent. To be sure, you should always check your local authorities' regulations for the exact guidelines before erecting your extension.
There are also fees associated with obtaining planning consent that you should take into consideration when budgeting for your project. In the UK, the typical cost of a planning application is £550 for the build of an entire new home, while extensions and garden outbuilding planning is £250.
What Fire Protection Regulations Need to be Followed?
Fire protection regulations are in place for the protection of any occupier in the event of a fire. By following these regulations correctly, there will be a reduced risk of a fire starting on your property and safe evacuation procedures in the case of one.
In previous years, there were several severe fire occurrences during the building and occupancy of a timber-framed building. Therefore, the Fire Safety Regulations Act came into existence.
Designers and developers must follow these principles when planning and constructing a timber-framed build to comply with the risk management of the development phase.
These regulations include using treated timbers in advance of constructing the structural timber-frame for the build, along with installing tested fire-resistant linings to all walls and floors.
Typically, a cavity barrier will be necessary between the internal timber structure and the external cladding material. A cavity barrier is a concealed space that will protect the structure from the penetration of flames and smoke, restricting the movement of the fire from attacking adjacent areas.
Most timber frame walls and floors will require a combination of fire-resistant lining boards along with other protective elements, being fixed to the internal structural framework of the building.
Consider that other appropriate components may also require protection, such as insulation materials, air gaps and electrical connections. Your qualified construction team will be able to inform you of the methods that will be used during your build. However, the best way to educate yourself on the requirements of the fire protection legislation is to contact your local authorities.
What should I look for when choosing a company to build a timber house frame?
"Longevity of experience and basic reputation. A firm that lasts the test of time with an unblemished record will almost certainly advise, produce, and fit in good time for the right price at a high standard."
Different Types of Timber Frame Extension
There are a few different types of timber frame methods to consider when planning your new extension.
The Platform Frame Method
The platform frame method of building timber frame structures benefits both low-rise and medium-rise raisings.
Many buildings up to 7 storeys in height have been erected, typically for residential and commercial uses, using the platform frame method.
This method of construction involves floor structures bearing onto load-bearing wall panels, thereby creating a platform for the development of the next level.
Pros
- ✔ Effective for multi-storey construction in both low- and medium-rise buildings
- ✔ Uses short timber lengths which are easier to source, giving a stable floor level for contractors to work from
Cons
- ✖ Horizontal load-bearing timbers may shrink, which in turn causes interior stress on finishes like plaster, leading to cracking
Vertical Panel Frame
Vertical panel frame methods are the most commonly used process for constructing smaller timber frame structures such as home extensions and garden outbuildings.
The process involves the erection of vertical timbers to create the supporting structure of the build. These timbers will form the panels of the internal support, fixing together to create the sub-structure.
Pros
- ✔ Straightforward panel assembly, reducing the need for skilled labourers
- ✔ Fast construction times, lowering overall labour costs
Cons
- ✖ Not suitable for large-scale projects or builds above single-storey structures
Volumetric
Volumetric modular units are construction elements that can be combined to form a whole building without the need for an additional supporting sub-structure.
Often, these components are manufactured off-site, either in a factory or workshop, and transferred to the construction site for installation.
Pros
- ✔ Factory-built quality, improving precision in the construction
- ✔ Fast on-site building as modules are already connected off-site
Cons
- ✖ Hard to transport large structures to site with high shipping fees, especially to more remote locations
Hiring a Timber Frame Extension Specialist Checklist
When the time comes to hire a specialist to construct your timber frame extension, here's what you should keep in mind to make sure you get the best professional for the job:
- Research local architects or designers to help develop the initial plans for your extension.
- Search for reputable, qualified tradespeople who will work on your project and gather at least 3 quotes to ensure you are receiving the best price.
- Be sure to ask about local building regulations and any requirements for planning permission, and ensure that your build is following the appropriate building and fire regulations.
- Make sure you get an itemised breakdown of costs, checking if waste removal, skip, and scaffold hire are included.
- Discuss your options for internal and external materials and methods of construction.
FAQs
Are timber frame extensions cheaper?
Generally, yes. Timber frame extensions are usually cheaper than a traditionally-built extension due to the fewer labour hours involved.
What's the cheapest house extension?
On average, the cheapest way to build a single-storey home extension in the UK is to use a timber frame method of construction with rendered cladding exterior.
How can I moderate the temperature of my conservatory?
There are quite a few ways – choose glass with sun-absorbing/-reflecting technology, choose a tiled roof instead of fully glazed, add lots of ventilation (doors, windows, vents), install a ceiling fan, add blinds and install underfloor heating. For less permanent heating solutions, you can always put in a portable heater.
Will I need planning permission for a timber frame extension?
Not necessarily. If your intended extension satisfies specific criteria in terms of size and location, then you may be able to build without planning permission.
Can I have a timber extension instead of brick?
Absolutely. There are many reasons why someone would choose a timber-framed extension over masonry. The reduction in cost and speed of construction are the primary advantages.
Will a timer frame extension rot?
It is rare for a quality timber frame building to suffer from rot, as external cladding elements should well protect the internal substructure and frame from weathering.
