Wooden Annexe - Cedar cladding with light and airy interior

Will I need Planning Permission to build accommodation in my garden? If your annexe is to be used as accommodation, you would usually need to apply for Planning Permission. “Each council has a slightly different protocol. However, as a general rule, a full planning application takes up to 10 weeks (pre planning applications less),” Andrew Guppy says. “You’re not necessarily restricted in the same way with heights as you would be if you were building a garden room under Permitted Development [maximum height under these rules is usually 2.5m],” Jakki Cosgrove says. “However, the scale of those parameters sits well in domestic environments. “Good communication with the planning department is essential,” she adds, “and pre-application guidance is generally available from local councils if you want to establish the principle before advancing too far into the project.” “Converting an existing building into a liveable space is always an option,” Andrew suggests. “It’s best to start by assessing its structural integrity along with its current insulation requirements, in particular the floor, which will probably need insulating along with the walls.”

In which circumstances could I erect an outbuilding without Planning Permission? “It is possible in certain circumstances to build annexe-type buildings under Permitted Development,” Abbie Elson says. The intended use of your outbuilding, as well as some other factors, will determine whether or not you need to apply for Planning Permission. “As long as the proposed use is incidental to the enjoyment of the dwelling house, then it would be acceptable,” Angus Eitel says. “In other words, it can’t be ‘primary’ accommodation. A home office, for example, falls within this proposed use.” Angus lists the following rules that buildings need to comply with for Permitted Development: No outbuilding on land forward of a wall forming the principal elevation (ie not at the front of the house or jutting out from the side). Outbuildings to be single storey, with a maximum eaves height of 2.5m, and a maximum overall height of 4m for a dual-pitched roof or 3m for any other roof. A maximum height of 2.5m in the case of a building, enclosure or container within 2m of a boundary of the curtilage of the dwelling house. No verandas, balconies or raised platforms (a platform must not exceed 0.3m in height). No more than half the area of land around the “original house” would be covered by additions or other buildings. In National Parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites, the maximum area to be covered by buildings, enclosures, containers and pools more than 20m from the house is limited to 10 sq m. “In order to avoid any confusion at the time of any property sale, we would recommend that owners apply for a Lawful Development Certificate to prove that any outbuilding complies with Permitted Development requirements,” Angus adds.