Building Control Regulations for decking projects.

Building regulations for decks come into play if there is a safety element involved - particularly at high level.

Building Regulations and Planning regulations are two different things - normally administered by two different sections/departments of your local authority.

Normally. a ground level deck does not need to be subjected to Building Controls - or Building Regulations. It is when the deck is raised from the ground - and adjacent to the house - that Building Inspector of your local council will want to become involved.

The prime purpose of implementing building controls on a raised deck, is to ensure that there is safe access and egress from the house - and then by implication, into the surrounding garden/grounds.

If you can simply step down from your house doo onto a patio, or direct into the garden, then there is generally no problem as far as the building inspector is concerned.

However, if you means of access to the house is by means of a raised deck - basically anything over 60cms (2ft ) - the the inspector will want to become involved. The inspector is normally concerned with the area adjacent to the house - and the safety of actually getting in and out of the house.

The general criteria for ensuring that a deck is built to Building Regulations standard, is to ensure the overall safety of people using the deck. So,

Construction has to be in keeping with the type of deck built. This will include
Proper support of the structure where it meets the ground - ie support posts firmly anchored either by a concrete footing or similar
Joists of the proper dimensions, properly fixed to the supports and to the house, to ensure that the deck is stable.
Minimum joist dimensions would be in the region of 150x50mm (6x2) at 600mm (2ft) centres. You will also have to calculate the span of the deck joists between supporting posts or support beams.

Balustrades and Staircases. Where the deck is 600mm or more from the ground >>>

Balustrade - railings - will normally have to be at least 1100mm from surface of deckboard to top of handrail. In other words 1100 high from the deck.
The balusters will need to be placed close enough together, to ensure that maximum 100mm (4in) gap. ie a 100mm diameter sphere should not be able to pass between adjacent balusters. This also applies to the gap between to balustrade and the deck surface - a 100mm sphere should not be able to pass under the balustrade. This will apply around the whole perimeter of the deck.
Staircases. There are regulations about the 'pitch' (steepness) of the staircase, the height of each step, the width of the tread and also how the step is constructed 0 to ensure a correct 'nose' on the tread.

These guidelines for building control regulations relating to decks are by no means exhaustive, but are meant as a general guide. With any type of raised deck, it is best to employ the services of a professional.