Insulated garden office with verandah

We recently completed this insulated garden office in our home town of Harpenden. With a hipped roof clad in cedar shingles and a verrandah for the client to hang his hammock, the office provides a good sized work space away from the clients two young chindren. Although the building required planning permission because it is higher than the 2.5m limit, this was readily granted. With 120mm of insulation in the roof and our standard 100mm thick walls and floor, the office has been very warm even during the recent cold. External cladding is vertical cedar and the decking is larch. The photo is not great but we shall be taking more if and when the we see the sun again.

When the Government changed the planning rules relating to outbuildings on 1 October last year we thought flat roofs were the only answer. So we designed a couple of flat roofed buildings to meet the demand: the Penthouse 8 and Penthouse 7.5. Both these Vivid Green buildings incorporate all of our design principles: low energy, low maintenance, plenty of natural light. Headroom is between 2075 and 2150mm (6’ 9” to 7’). Both buildings offer attractive space for an office, studio or workshop.

Penthouse 8

Penthouse 7.5

However, over the last few months we have designed several other buildings for customers who wanted to site the structure close to one or more boundaries but liked the idea of a more attractive roof shape. The following sketches give an idea of the options available if you can leave at least one metre between your boundary and the wall of the building.

Flat roof & lantern

Flat roof with lantern

The simplest way of adding headroom and light is a lantern. Glass lanterns can be very expensive but we have found a polycarbonate version which offers a great alternative. Double and triple skinned versions offer superior thermal and sound insulation. Headroom is typically 2075 to 2150 (6’ 9” to 7’) plus an extra 300-500mm (1’ -1’ 7”) under the lantern.

Shallow hip

Shallow hip

A shallow pitch of at least 15 degrees offers the option of cladding the roof with cedar shingles and just a few more degrees opens up lots of options including eco-slates (imitation slates manufactured from recycled plastic). Because of the need for a slope, the height of the walls (eaves height) is reduced but greater headroom can be achieved throughout the rest of the building. Typically 1800mm (5’ 10”) at the eaves, headroom increases to 1930mm (6’ 4”) 500mm in from the walls and is 2600mm (8’ 6”) in the centre.

Shallow hip + gablets

Gablet roof with porch

When the garden is a little bigger there is the potential to add ‘gablets’ to the roof: triangular gable ends. These can be left solid but, using triangular windows makes a very attractive roof shape and provides additional light. Headroom is similar to the shallow hip design above.

Both shallow hip designs require one wall to be inset by approx 600mm to allow installation of doors. This creates an attractive porch or veranda depending on size

For more details, call or email us: 01582 469076 or neil@vividgreen.co.uk

Planning guidance

If you want to know more about planning regulations take a look at this web site: http://www.planningportal.gov.uk/wales/genpub/en/1105619048902.html