What's the best roof type for my home extension?

Mention the phrase ‘home extension’ and people’s thoughts immediately turn to such subjects as bifold doors, open-plan living and Scandinavian-inspired furniture. In reality, though, one of the first considerations should actually be the roof, as that is one element that will account for a large part of the budget. It could also be the main cause of ongoing issues such as leaks if not designed and installed correctly.
Tastes change, and the correct roof style – whether flat, pitched, glazed, thatched or ‘green’, for example – will to a great extent depend on the age, style and location of the property. The planners will ultimately decide on the suitability of the roof, but it’s worth considering all the options at design stage and, as one of the leading Cambridge builders, at Refresh we’re perfectly placed to guide you through this potential minefield. In this article we consider the options available when it comes to roofing styles and examine the benefits and drawbacks of each choice.

Flat roofs

A flexible, simple and affordable solution, flat roofs are very popular for extensions of any shape or size. Felted flat roofs are easy to insulate but they do offer an increased risk of leaking and have a shelf life of only ten to 15 years as opposed to the 20 to 30 years that a pitched roof might last. Flat roofs tend to be less popular with planning departments, who will usually insist that they are only applied to rear extensions, but they do make installing spotlights more straightforward, albeit by sacrificing additional loft space or ceiling height.

Inverted flat roofs

Inverted flat roofs have a longer lifespan than conventional flat roofs as they incorporate a waterproof layer with paving or other material over the top. The beauty of this approach is that as well as extending the roof’s life, this solution is sufficiently solid to be used as outside decking or balcony space providing planning permission for that use has been granted. A stipulation of the decking or balcony use may also be that you have erected a protective rail or barrier to prevent injury through falls and that you have converted a suitable window into a door to provide easy access. One final consideration here is that planners will be concerned to avoid or address potential overlooking of the neighbours’ properties.

Pitched Roofs

Frequently the default option, pitched roofs have a number of benefits, including the angle to encourage rain to run off, the ability to achieve extra ceiling height and loft space for storage, and the scope for making an architectural statement both inside and out. Most architects and planners will agree that pitched roofs are more attractive than flat roofs as they can incorporate traditional tiles or artificial slates. And from an internal perspective they provide the flexibility for exposed joists, funky ceiling angles to reflect the shape of the ceiling and rooflights to create a light and airy space. Pitched roofs will, however, require a larger budget due to their complexity and the materials required to complete the roof.

Glazed Roofs

With an expanse of glass, glazed roofs are a brilliant way to flood an extension with natural light and create a conservatory-style space cocooned with brick walls. Glazed roofs are also a stunning architectural feature and a serious talking point, especially when used for a kitchen, studio or home office. Unless your property is already overlooked, there is a minimal effect on privacy, but there will be a need to demonstrate to planners that the roof has suitable u-value levels to ensure that heat is not lost through the roof too quickly. Planning departments will insist that a glazed roof is sympathetic to an existing property, and their use may be restricted on listed buildings and in conservation areas.

Thatched Roofs

The decision to thatch your extension roof will invariably be dictated by the type of roof in place elsewhere on the property, and there are pros and cons to be considered. Thatched roofs use natural materials which can undulate more than rigid roof tiles, so it is possible to create interesting flows to the roof. In addition, the natural materials will darken over time and further blend in with the natural surroundings. Offering a lifespan of ten to 15 years, thatched roofs also self-insulate, removing the need for synthetic insulation in the roof space. All in all, they are the most environmentally-friendly roof solution available, but they do require a larger budget as they are labour intensive to install. They require an annual inspection, they usually inflate your insurance premiums due to the increased risk of fire and they must be positioned away from overhanging trees to prevent excessive drying.

Green Roofs

Increasingly popular in urban areas but also becoming a must-have feature in rural settings is the green roof, where the manmade surface is covered with a natural habitat for plants and wildlife to grow. Planning departments look very favourably on green roofs, especially within built-up environments, as they are deemed to be both environmentally friendly and aesthetically pleasing. There is no doubt that a green roof will require more maintenance than a standard roof, but the level of work needed can be mitigated through careful planting. Green roofs are also more expensive than conventional alternatives and are invariably flat, but it goes without saying that they create a certain wow factor.
As Simon Kelliher of Cambridge builders Refresh Renovations confirms, it’s crucial to have a clear understanding of the positives and drawbacks of each type of roof before pushing ahead with a home extension. ‘At Refresh we have experience of all types of roof,’ says Simon, ‘and that can be a real benefit for our clients. When selecting the best option, it’s important to take into account the location, the climate, the surroundings and, of course, the overall budget. We encourage clients to weigh up the practicality against the wow factor as roofs are expensive to install and it’s worthwhile to ensure that maximum usage and lifespan is achieved.’
Contact Refresh about your renovation
Want to know more? Get in touch with the renovation experts at Refresh now to find out what they can do for you and your home. Refresh Renovations Specialists offer a free initial one-hour consultation that will help you make the decision whether their team is the one for you. This consultation is no obligation and is a chance to understand what they can do for you.