How to build a garden office: Quick guide

Garden offices are becoming increasingly popular as they offer a quiet area to work from with access to a main properties amenities. They are especially popular with larger households, who need a professional working environment away from the home, and those with more outdoor space.

With the growth of remote working, many homeowners are seeking the assistance of builders to help transform their garden space into a functional office, complete with design trends and eco-friendly features.

This guide will take you through how to build a garden office for your clients, including planning permissions, estimated costs, building tips and essential tools and materials. 

How much does a garden office cost?

The cost of a garden office varies depending on several factors, including the size of the office, materials used and level of customisation. A garden office costs anywhere from £5,000 to £50,000. 

A small timber garden office with essential features such as insulation, wired sockets and lights, and house-quality windows and doors averages around £8,000. While the design will be relatively basic, the result is a functioning garden office your customers can use throughout the year.

Using higher quality materials, such as cedar cladding, or building additional features like floor-to-ceiling glazing and interior plastering costs slightly more — usually between £20,000 to £30,000.

A fully-customised garden office with high-end finishes and advanced technologies usually starts at around £40,000, or between £1,400 to £3,000 per sqm. This office type may include solar panels, underfloor heating, and bi-fold doors.

Some contractors also charge an additional fee for installing the base or foundation of a garden office and any extra decorating tasks. 

As garden offices are high-investment home additions, it may be worth considering financing options in terms of payment. If this is offered, homeowners may be more likely to opt for a unique and higher-quality structure. 

How much does a garden office add to the value of a house?

As floor space is a significant factor when valuing a property, a garden office's extra space can raise a home’s value. The exact increase depends on several specific details, including the size, quality, and location of the garden office and primary property.
 

Top tips for building a garden office from scratch

Before undertaking any garden office project, it’s important to remember these top building tips. Remember though, every project is different - seek appropriate specialist advice if needed and always follow manufacturer’s instructions.

• Choose the location wisely – Ensure the location of the garden office complies with any regulations, and consider how often the homeowner will use the outbuilding. For example, if they plan to be in the garden office daily, put it in a sunnier spot for added warmth.
• Have a detailed plan – A detailed plan is crucial. Consider building regulations and planning permissions, and create detailed drawings that accurately reflect the garden office's size, design, and layout.
• Use high-quality materials – Using the best materials available within the homeowner’s budget ensures the garden office is durable and weather resistant. This will prolong the life of the outbuilding.
• Consider the foundation – Using a durable foundation material, such as concrete, ensures the stability and longevity of a garden office. For best results, appropriately prepare and excavate the site. 
• Use energy-efficient features – As a builder, staying up-to-date with the latest energy-efficient building materials and techniques is essential. Consider adding roof and wall insulation, renewable energy heating and cooling systems, and triple-paned windows to the garden office.
• Take care with electrics and plumbing – To ensure the garden office is adequate and comfortable, equip it with proper electrical and plumbing systems, including sockets, running water, and lighting, installed by an appropriately-qualified person.
• Don’t forget aesthetics – Pay attention to the aesthetics of the garden office. Consider ways to blend the outbuilding with the surrounding environment or match the main property.
• Make maintenance easy – Making a garden office easy to maintain is beneficial for both the builder and the homeowner. Use low-maintenance materials and plan for easy access to the building for any repairs or cleaning.
• Prioritise safety – Building a garden office is a large project, and you should take safety precautions. Ensure all site workers are adequately trained and equipped with safety gear.
   

How to insulate a garden office

There are several methods to insulate a garden office, making the room warm, comfortable, and suitable for use year-round. When installing insulation, seal any drafts or gaps to ensure maximum efficiency.

The insulation method you choose depends on the homeowner’s budget and available materials.

While higher quality and more sustainable materials are more expensive, it’s essential to remind the homeowner that better insulation will save them money in the long run. A well-insulated garden office will benefit from a longer life span, fewer maintenance requirements, and lower heating costs.

How do you heat a garden office?

You can heat a garden office using various methods which you, as the contractor, can either install or advise the homeowner to implement.

• Electric convection heating – Electric heating is one of the most popular ways to heat a garden office, as it’s easy to install and can be powered by a standard electric outlet. They can either be freestanding or wall-mounted and controlled by a thermostat if desired. Electric heaters warm the air quickly, which is ideal for chilly mornings during winter months.
• Electrical oil-filled heaters – Oil-filled heaters have come a long way since the bulky contraptions commonly installed in basements. Nowadays, they are light, portable, and easy to run. Oil-filled heaters work by submerging an electric heating element within the oil, which heats and circulates it. They have heat-trapping elements, which means they often retain their temperature even after they’ve been turned off. Oil-filled heaters are also much cheaper to run, and there’s no need to refill them.
• Underfloor heating – Underfloor heating is usually advised as a secondary heating source. It runs on a mesh element fitted below the floor and is more effective in retaining heat surfaces, such as concrete or tile. 
• Solar heating – Solar heating functions either actively or passively. Passive solar heating involves warming the room using south-facing windows or large skylights, while active solar heating utilises solar thermal panels, turning solar energy into heat. Roof-mounted tubes are used to warm water and feed an internal radiator. While this option is more environmentally friendly, it is not always practical in less sunny locations.
• Air conditioning – Air conditioning can heat and cool a room to maintain a comfortable temperature year-round. Modern air conditioning units don’t require large refrigeration units and are smaller and quieter, making them suitable for garden offices.
• Wood-burning stove – Wood-burning stoves are popular for homeowners who want to add a fashionable element to their garden office. They can choose from several contemporary or classical styles and use various fuel sources. However, a chimney flue can be expensive, and a stove may require more maintenance than alternative heating methods.
• Infrared – Infrared heating works by heating the objects in a room rather than the space itself. This heat is transferred between objects and lasts longer than traditional methods. As infrared heating requires positioning the heater in an optimum spot, it’s advised to make it portable or easy to move.

Outline and discuss these heating options with the homeowner before you start building. That way, you can incorporate methods into the design and construction of the garden office that best suits their needs.

Ways to ensure an eco-friendly garden office

Many homeowners are requesting a more eco-friendly garden structure. Luckily, many building materials and techniques achieve this. 

One of the best ways to ensure an eco-friendly garden office is to build the structure using sustainable materials. Source wood from sustainably-managed forests, or choose materials with low environmental impact, such as bamboo or cork.

For insulation, choose an eco-friendly method, like sheep’s wool or hemp. These materials are more sustainable and have higher thermal performance, meaning the homeowner will minimise their heating use.

You can use large skylights and many windows to increase a garden office's environmental friendliness, as it reduces the need for artificial lighting. If you need lights, use energy-efficient light bulbs, or install motion sensors that switch off lighting when it’s not being used.

Install renewable energy sources to power and heat the garden office and reduce its carbon footprint, such as solar panels or wind power. If installing a bathroom or kitchenette, opt for low-flow fixtures to save water.

You can also make any added decoration and finishing touches eco-friendly. Use sustainable paints with low-VOC (volatile organic compounds) mixtures to improve indoor air quality, or incorporate green roofs and living walls into the garden office design. Plants help reduce the structure’s heat island effect and filter air pollutants. 

Garden office ideas and inspiration

There are many places to find garden office ideas and inspiration. While your client will come to you with a rough idea of how they want the structure to look, researching and advising on specifics can aid the design and building process. 

Several online blogs are dedicated to garden office design, such as The Garden Office Guide and The Garden Room Guide. You’ll find a range of inspiration, from small garden rooms to those with bathrooms, kitchenettes, and soundproofing.

A quick search on Pinterest will reveal thousands of garden office design suggestions curated by architects, builders, and homeowners alike. Start your board and collect your favourite images to show your client.

Attending home and garden shows lets you see the newest and most popular features of garden offices, which you can implement during your builds. From sustainable materials to modern designs, staying up-to-date with the latest industry trends is integral. 

Finally, you can chat with local architects, builders, and other industry professionals specialising in garden office design. Talking to other professionals will give you a good understanding of the most recent garden office trends and offer a chance to swap tips and tricks for building the best garden office.