// Design & Build


Our homes are an extension of who we are.

Kitchen Island Extensions

Times change and many of us are looking for modern, bright home environments that provide space and flexibility.

Though most homes were originally built to be functional, we know that with care and attention to detail even small home extensions can create a new and vibrant haven for family life.

Opening up new possibilities in your home

An extension completely transforms the way you interact with your living spaces. Are you looking to create a new breakfast area to brighten your mornings, experience the charm and delight of a spacious kitchen diner, or open up more space for the kids to play?

  • Light and fresh open plan living

  • Merging indoor and outdoor spaces

  • Studies, dens or home cinema rooms for work, rest and play

Transform & expand your living space

Extension Types

There are multiple types of extension to fit different requirements and budgets.
Below are the most common types of extension you may consider:

Single story, front, side and rear extensions

Double or multiple storey extensions

Garage conversions and extensions

Basement conversion

Outbuildings and orangeries

Build around your lifestyle

What you want to achieve? - is it to gain more space? increase the value of your property? make better use of the current floor space?

When extending the possibilities can be overwhelming, so having a clear goal from the outset is essential to a successful build as it will guide the decisions you make throughout.

  • Our discovery process will help you determine the project purpose

  • Ask us about our goal mapping process to help you gain clarity on what you want from a home redesign

  • Our bespoke design ideas for kitchens, bathrooms, bedrooms and open plan living will help you narrow down choices that fit your vision

Make the most of the newly legislated: Larger Home Extension Scheme:

If you are planning on building a single storey rear extension under your permitted development rights, you can now take advantage of a doubled size allowance under the Larger Home Extension Scheme. This includes extensions up to 8 metres (from 4 metres) for a detached house, and 6 metres (from 3 metres) for all other houses.


Extending a property with the addition of a new bedroom boosts a typical home’s value by 11.2% or £25,383 based on an average UK house price of £226,0713.

Source: Hiscox Insurance Brokers

We take care of everything from day one with our end-to-end service

We offer an end to end building service and can take you through the whole process from planning and design to construction and completion. Alternatively are also happy to work with your chosen architect or from existing plans.

We only ever take on a small number of projects, ensuring we take a hands on approach to all aspects of the build, delivering on time and on budget.

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Initial Consultation

From initial consultation through to completion all our building projects must deliver value. There are numerous factors and moving parts that dictate the success of a project outside of time, scope, and budget. We aim to ensure our clients have a clear understanding of all the elements involved in order to make an informed decision to engage our services.

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Design & Planning

The design and planning stage moves ideas and objectives to a concrete course of action. You may or may not have plans and approval for your project, either way design and planning is where inspiration and and imagination come together to help you visualise what you want your home to look and feel like once the project is complete.

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A build project managed by Keystone means that from conception through to completion, everything is managed through a single point of contact. We coordinate all the required professionals from architects and structural engineers, to contractors and building control. Streamlining the process, saving you time and money.

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We pride ourselves in delivering exceptional customer service before, during and after a building project. Aftercare is offered to all clients following successful completion of their project and on-going property maintenance is available as a service to both existing and new customers.

Common Questions: Extensions

You are making an investment decision and asking the right questions will help you ensure you understand the costs and potential hurdles involved in realising the potential of your building project. We will help you understand what is involved before, during and after the process. As a guide here are a few questions that often arise:

Not all types of extension require planning permission, such as glass extensions or loft conversions. It largely depends on the general size and location. We can help you understand all local planning regulations and requirements before making any decisions or proceeding with the extension.

This will depend on the type of extension being planned, for example planning single-storey side house extensions will likely be quicker than the time required to outline a two-storey wrap-around house extension. Whatever your vision, our team strive to help you make the planning process quick and efficient.

Regardless of whether your project requires planning permission or not, most house extensions throughout the UK need approval under the Building Regulations 2010. This is especially true when planning to replace or install windows, doors, electrics, heating systems, plumbing and roofs. We will help you to establish the exact approvals needed from your local authority.

During the planning stages of your house extension project, your neighbours will be able to express any concerns they may have, particularly if you are making major adjustments to your property. What is more, they may be disturbed throughout the construction period so it is important to keep them informed of your intentions from the start.

For jobs such as extensions and conversions, the best formula is the square metre rule – generally, build work will cost between £1,500 and £2,500 a square metre, but local factors may affect the price for your project and your level of specification will have a bearing.

We make sure your quotation is as thorough and detailed as possible, ensuring that we have explored all possibilities and potential issues so that the costings are as accurate as possible.

Still looking for answers? Get in touch with our specialists.

Speak to us >

Speak to our Extension Specialist

We are happy to discuss your extension project and answer any questions you have. Please leave your details and a message below or alternatively contact us by phone.

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