Pergola: Frequently Asked Questions

These are the most common questions I came across when researching my use of Pergolas.

A pergola is an outdoor structure designed to offer shade. It is often quite stylized and is frequently referred to as ‘adding an extra room outside’. It consists of pillars or posts that then hold a frame above head-height. A basic design would then have a regular array of crossbeams that go from one side to the other of the frame offering shade but with significant gaps to allow light thru and to maintain a bright airy feel. Other methods of creating the shade include adding shade cloth to the frame, growing plants up and over the structure or using other raw materials to cover the space between the crossbeams.

For more in-depth information then check How does a Pergola Work? or Top 14 Why’s, Do’s and Dont’s to having a Pergola.

‘Freestanding’ simply means that the pergola is not attached to any other structures. Freestanding Pergolas are usually located in gardens or yards where the entertaining area to be shaded is not directly next to the house. It is, however, perfectly possible to buy a freestanding Pergola kit and install it next to your house, to give shade over the desired spot, but not actually attach it to the property.

The significance of being freestanding is usually only relevant to the construction and will require the Pergola to use its own posts/pillars to support the roof frame. Rather than, for example, attaching a rafter along the outside edge of your house and using that to support one side of the Pergola roof.

Most Pergola kits will be Free Standing.

Open-sided Airy StructureMore Substantial StructureOpen airy structure, usually located for a particular view.
No Solid roof but has various options for adding shadeSolid RoofSolid Roof
Flat Top Usually PitchedPitched
Not RainproofRainproofRainproof
Attached or freestandingAttached or freestandingFreestanding
Square or rectangularSquare or rectangularUsually Circular style with 5 – 8 sides
Usually, does not need planning permissionProbably Does need PermissionProbably Doesn’t need Permission

Both are open and airy garden structures that do not have solid roof structures, instead having a series of crossbeams often forming a grid pattern. They differ mostly in size and in there use.

Pergolas are meant to offer shade and tend to shield a larger area. This may be freestanding or attached and can as a walkway or simply as a dedicated area for relaxing/entertaining.

An Arbor is more of a smaller decorative feature. They may be arched (but not necessarily) and are often used to mark an entrance to a section of the garden/yard. They may also be fitted above or include a bench and used in scenic areas.

Both forms are commonly used to grow vines or other climbing plants that can grow over the structure with Arbors often having a latticework up the sides (as well as the top) where a Pergola would only have posts/pillars.

The suggested height of your pergola is dependent a little on the total size, with larger structures being taller. Having said that a normal height would be in the range from 7′ / 2.1m up to over 11′ / 3.35m depending on the size and the location. The minimum should be 6’8 / 2.05m which is the same height as a doorway.

Other considerations to the aesthetics, such as the Golden Ratio (length is 1.618 times the height), may also help you decide as well as other factors such as attached Pergolas being below the roofline.

A Pergola with a solid roof can also be called a Ramada or possibly a Gazebo.

All three are garden structures but a Ramada and Gazebo have solid, usually pitched, roofs and offer protection from the rain as well as shade from the sun.

It is, however, common to find companies offering waterproof covers for Pergolas, this may not be strictly adhering to the Pergola definition but are usually where they maintain the same open, airy appearance or where the covers are added after the initial build.

Yes, depending on where it is to be located. Although they are much lighter than an equivalent structure with a solid roof it is still necessary to secure your Pergola, to stop it sinking into the ground and to stop it blowing away! Footings are designed to spread the load of a structure and to attach it firmly to the ground. If you are building a new freestanding pergola in your yard/garden then you will need to have footings to support each post/pillar and to anchor the finished structure to the ground. If, however, you are building it on top of an existing platform ie a concrete slab, patio or deck then you may already have a suitable footing to which you can attach your pergola. However, as it may not have been built with a Pergola in mind it is worth considering if it needs reinforcing?

The size of a new footing for a post will depend on your structure but as a guide they should be at least 1/3 as deep as the post is high above ground level and at least 12 inches (30cm) wide. Check with a local builder to get local advice based on your specific area and pergola size. Example: In areas where you have a heavy ground frost the footing would need to be at least 12 inches below that level.

Any concrete pad that you are planning to attach to should be at least 4 inches in depth.

Note: In the USA be sure to ring 811 to get a free local utility survey before starting digging!

In most cases, the location of your Pergola will be limited to one spot but it is possible to adapt the design to make it the most suitable for your particular requirements.

As the sun is continuously moving the location and amount of shade that any structure offers will also be constantly changing. Deciding when (eating lunch outside, reading in the afternoon, entertaining in the evening) you are most likely to want the benefit from the shade is the starting point. You can then adjust the height and/or direction of rafters or crossbeams to make them perpendicular to the sun at that time of day.

If you have more flexibility in the location of your Pergola then consider that the effects of the sun are usually most intense in the afternoon. This is when the ambient conditions have had all morning to warm up and as the sun starts to get a bit lower it will shine directly onto walls (as opposed to being higher in the sky). If you are using the Pergola to offer shade for the house as well, then placing it on the southwestern side ( in the northern hemisphere) will gain the most benefit.

Yes, but not completely. They are designed to allow light below and let hot air escape whilst still offering an amount of shade. They are airy structures that can use one or more of several methods to shade the area underneath. These can include crossbeams and rafters to form a lattice-like grid, plants growing over the top, shade cloth or any variety of raw materials (driftwood, bamboo, rushes, etc) laid across the frame.

For a more in-depth answer then please check out Do Pergolas Really Block the Sun?

Depending on the format of the Pergola it can offer protection from a very light rain but they are not normally designed to be rainproof. As an airy open structure with a lattice style roof that lets light below and hot air to escape, they do not block the rain. For a solid rainproof roof, you may prefer a Ramada or Gazebo. See the FAQ above for What is the Difference Between a Pergola, Ramada and Gazebo.

As with anything, there are lots of examples that do not fit the rule! There are now many companies that offer rainproof covers for Pergolas or retractable installations that can give you the same look and feel of a Pergola but the added benefit of being rainproof when required.

This obviously depends on your local building regulations and you need to check as they may have specific requirements about total size and distances from public roads, utilities, fences, etc

However, in most places, the accepted definition by planning authorities is that a pergola is not considered a permanent structure. In most places, the concern is going to be over the height and as pergolas have a flat-top and do not have a pitched solid roof, that can interfere with sightlines of nearby properties, they often get treated more leniently than those structures that do, such as a Ramada.

If you are planning an attached Pergola then there may well be additional regulations relating to the fixings and method.