01625 875588 support@swiftorg.co.uk


Annexe Technical Information

We want to help you achieve your perfect annexe within your preferred budget. So in order to help you, we have prepared a summary list of features that are included as standard within your Swift Annexe.  The information below gives you a general idea of the standard materials and finish we offer.  However, as we pride ourselves in a bespoke service, we fully appreciate that you may wish to select your own alternatives for your living annexe.  Naturally, we’ll work with you if this is the case.


As standard your building will sit securely on helical screw pile footings. These are driven into the native ground and are designed to keep your building slightly elevated to maintain airflow around the structure, to aid the building’s longevity. All screw pile depths and spacings are carefully engineered to ensure ‘Point Loads’ (weight) is distributed evenly.  Screws are also much better for the environment than concrete and other systems, with no waste created during installation.  For your peace of mind, all screw piles are compliant with current building regulation requirements and structurally engineered to ensure they will support your new annexe indefinitely. 

Sometimes screws may not be suitable for your ground conditions, for example the building may be directly on top of native bedrock.  In cases like this, we can choose from a wide range of other footing systems which would be better suited for your specific environment.  Other footings systems include adjustable footings, rafts, slabs and ground beams.  Rest assured that our expert surveyors will explain which footing system will be best for your building.

“They could not have been more conscientious if they had been working on their own property.”

DW, Cheshire



The main structural elements of your building are constructed using BBA Approved, Structurally Insulated Panels, or ‘SIP’ panels for short. These panels are structurally engineered and offer unrivalled strength and insulation properties. They are manufactured to your exact needs from one of the UK’s largest manufacturers/suppliers, who we have shared a strong working relationship for many years.

Walls, roof and floor structures vary in thickness dependant on the level of structural support and level of insulation required, which is usually determined by a qualified, structural engineer. We typically install 125mm panels as an absolute minimum on our annexes, giving you excellent thermal efficiency and meeting all current building regulations for comfortable, year-round living.


“The team worked extremely hard in all weather and were responsive to any questions or concerns we had. They communicated clearly when they needed to and always left things as tidy as possible at the end of the day.”

RK, Farnsfield

garden annexe build


granny annexe interior, window detail


All of our doors, windows and skylights are powder-coated aluminium, with argon-filled double-glazed, heat reflective coated glass as a minimum.

We have worked closely with our glazing suppliers for many years and they understand and satisfy our demanding quality standards. We can offer sliding, casement and bi-fold doors, as well as special requests such as bespoke coloured frames, structural glazing, bespoke glass artistry and triple glazing to name a few. You can even have blinds integrated into the glass itself if you so wish!



All of our flat-roof buildings come fitted with a Firestone cover- an industry leader in synthetic rubber EPDM roofs. The Firestone EPDM comes with 20-year manufacturers guarantee and 60+ year life expectancy.

All of our installers hold an external installation qualification with Firestone, which demonstrates they are both competent and experienced in the installation of the membrane, so you know you are in safe hands. If you would like to go for something a little different, you could always choose a sedum (living) roof or a pitched roof with lightweight composite tiles.  


sedum roof
EPDM roof on a garden room
EPDM Rubber flat roof
roof and guttering on garden room
Pitched roof with roof light


All of our buildings have half-round guttering to eaves with down-pipes, directing rainwater into a gravelled soakaway or your existing drainage. Square-line guttering, metal gutters, rainwater harvesting tanks and water butts can also be installed to manage rainwater. We can even top up your pond if you have one!



We offer numerous external cladding products, including natural materials such as western red cedar and larch, through to composites and renders. Each vary in maintenance, but most choices are very low. We can even supply ‘burnt’ cladding, stone and ‘living’ walls to attract local wildlife – a lovely feature to enhance your garden living lifestyle.


composite cladding on a garden room


Our annexes are fully finished ready for you to move straight in. All walls and ceilings are plastered and painted in a neutral white and your choice of quick-step laminate or vinyl flooring is installed then finished with skirting boards. Wood-panelled walls, decorative skirting boards and architraves are available if required – We can even offer acoustic treatment for added peace and quiet… Simply let us know what you need.

Living annexe interior


All doors are key operated, multi-point locking doors with anti-break Euro 3* barrels. Key operated locking windows to insurance-approved standards are fitted as standard. Hard-wired security alarms and security lights can be fitted to keep your personal belongings safe.


All of our fixtures and fittings are high quality from reputable suppliers. Our Collinwood LED spotlights are fitted both inside and out, with matching brushed steel sockets and switches with USB chargers as standard. All electrical works are undertaken and certified by our qualified electrician, meeting current building regulations and ensuring all electrical items are safe and compliant. We also take care of the connections from your main property to your annexe, so you don’t have to. You can even opt for remote control lighting and concealed TV points.


In order to stay connected to the outside world, you may wish to have Wi-Fi installed into your new home. We offer hard-wired internet which is taken from your main property direct to your annexe, which ensures you get the same internet speed as the main house. If Hard-wired internet is not an option due to the route or location, we can offer alternative solutions to ensure you stay connected – this can be via a microwave dish or 5G routers. We can advise the best option for you.



We appreciate your new annexe will be your home, so we aim to make your space as comfortable as possible for you. There are many options when it comes to heating and cooling, and our expert designers will take you through each one to help you make the correct decision based on your individual needs. You can opt for underfloor heating, radiators or air-conditioning units – all of which can be controlled remotely via apps on your smartphone if needed!


heated towel rail
External air conditioning unit


All of our annexes come with modern bathrooms.

Depending on your needs and budget, we can offer suites from our standard range through to fully bespoke. We undertake all plumbing works and water/waste connections, discussing with you the best options for each before we even start the build, so you know exactly what to expect.

annexe bathroom
annexe bathroom
granny annexe bathroom


Swift offer a standard range of kitchens which ‘cater’ for all!

We undertake the full design and install – including all connections and certification – whether you choose from our range or go fully bespoke, we will work with you to achieve your dream kitchen in your new annexe.

garden annexe kitchen
Living annexe kitchen interior
granny annexe kitchen
granny annexe kitchen


Our client’s safety long after we complete is of upmost importance. This is why we install hard-wired smoke alarms and windows and doors that double up as compliant fire exits in case of an emergency. During the build, we instruct independent building inspectors to attend site to ensure we are doing everything correctly which is then certified, and a copy given to you.

We provide you with an electrical certificate on completion, as well as a structural warranty – we know we are good at what we do so we have nothing to hide. Can the same be said for others?  


Your Swift building is a beautifully made and expertly installed permanent structure. As standard we provide a 10-year insurance backed structural warranty against material defect and faulty workmanship. The insurance is there as a safeguard in the unlikely event of Swift not being able to fulfil its obligations through liquidation – it also protects your deposit that is paid upon confirmation of your order. All this part of our customer-focussed package to you.