Make sure of the “rules” before building a conservatory or orangery

Why do some UK home owners still take the real illegal risk of erecting a conservatory or orangery without consent? Or why would a property owner build a larger conservatory or orangery than they should, somehow expecting to get away with it, purely because a “neighbour” had previously broken the planning laws and seemingly gotten away with it, or “their builder” had allegedly told them they did not need planning (like builders are experts on planning laws!).

Whilst it is totally wrong that some property owners have got away with it in the past, it does not make building an illegal conservatory or orangery right, especially now the planning laws and building regulations have been significantly tightened. It is not so clever nowadays, if having spent between ten and say fifty thousand pounds on a conservatory or orangery, a home owner then gets an enforcement notice to demolish it or reduce it in size! Some chap in Beaconsfield in Bucks built a large non-approved conservatory onto the rear of his premises, which obviously cost him a fortunate, but not as much as it eventually did, as he had to pay out three times. Once for the initial build, once for the demolition, and once for rebuilding a smaller conservatory with a lower roof.

Understanding what you can and cannot build conservatory and orangery wise is worth finding out

Understanding what you can and cannot build conservatory and orangery wise is worth finding out

Understanding the many conservatory planning “rules” can be a bit of a minefield in itself, as getting actual definitive answers from a local council’s planning department on what one can and cannot build onto a property is almost impossible, as most tend to say the only way you can know for certain is to make a formal planning application to your local council’s planning officers.

Many councils in the Home Counties have different rules, and different interpretations of the conservatory planning laws, plus each property can have it’s own unique location, materials and circumstantial criteria that may even vary from the neighbour’s property next door.

As an example, lets take the London Borough of Hillingdon’s guidelines for building a conservatory or orangery. According to their “Design and Accessibility Statement”, any new structure should “always be designed so as to appear subordinate to the original house. For terraced and semi-detached houses with plots less than 5m wide, a 3.3m projection is acceptable, or 3.6m projection if the plot is more than 5m wide. Detached houses can have a projection of 4m.” All these projections assume that the position of the conservatory or orangery does not interfere with each neighbours right to light. It is worth remembering that all conservatory width and depth planning limitation dimensions based on the total width or depth including guttering, so the internal dimensions obviously need to be reduced to accommodate the width of any guttering.

Any new conservatory or orangery built in Hillingdon Borough Council’s area must not result in any significant loss of daylight, sunlight or outlook to neighbouring properties, and it must not extend beyond a 45-degree line of sight taken from the middle of the nearest neighbours kitchen window or habitable room. Most local authorities in the Western Home Counties, such as Wycombe District Council and South Bucks District Council planning departments tend to operate a 60-degree rule, so it is important to check what your local councils planning rules for conservatories and orangeries are.

Each new conservatory or orangery must conform to the Garden Space Standards, retaining at least 40 sq.m. of the garden after a conservatory or orangery is built onto a two bedroom house, 60 sq.m. in the case of a three bedroom house and 100 sq.m. if built onto a four bedroom house.

There are height limits for conservatory and orangery roofs. Again as an example, Hillingdon Borough Council state that “the roof should not exceed 3.4m at its highest point. Generally roof designs must not significantly obstruct sunlight and daylight to any adjoining neighbour’s property.” The roof must be glazed in a material of 75% translucency, whilst vertical glazed surfaces must cover a minimum of 50% of the total vertical area. All vertical glazing within 800mm of the floor must be glazed with toughened glass.

To avoid having to apply for Building Regulations, any new conservatory or orangery needs to have an internal area no greater than 30 sq.m. plus have an independent heating system (if it has one at all), and there must be lockable external doors between the conservatory and the existing property.

According to the Hillingdon Design and Accessibility Statement, the Building Research Establishment’s report “Site Layout Planning for Daylight and Sunlight 1991? recommends that suitable daylight to habitable rooms is achieved where a 25-degree vertical angle taken from a point 2m above the floor of the fenestrated elevation is kept unobstructed.

Ventilation is a very important constituent part of any new conservatory or orangery, the more the better. Roof vents are highly preferable, as they act as a chimney, allowing the heat that always builds up under a conservatory or orangery roof to escape. Officially, the rules on ventilation for North facing conservatories, require openings of 15% of the floor area, and for South facing conservatories, openings of 25% of the floor area are required as a minimum (it is wise to build in as much ventilation as possible if you want a pleasant and habitable room on hot sunny days!).

The above guidelines represent only some of the many conservatory and orangery planning rules, so if you are planning to build either, or want advice on whether or not you need planning permission for a future conservatory or orangery project, simply request a free no obligation consultation from an experienced design expert.