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Conservatories are a popular addition to houses. The trend for adding conservatories started in the mid 1980's and became very popular in the 1990's and 2000's.



Conservatories are a popular addition to houses. The trend for adding conservatories started in the mid 1980’s and became very popular in the 1990’s and 2000’s. Conservatories are temporary structures and cannot be expected to have the same longevity as the rest of the building.

We are now inspecting houses where the conservatory is quite old and may have problems or have been altered. Conservatory defects are becoming more common and remediation is often costly. Our surveyors are trained to spot defects and give you the advice you need.

The cost of replacing a conservatory can range from £5,000 for something small and cheap to £75,000 for a large, high quality build. On a typical suburban semi, £25,000 would be fairly normal. It is important for our survey reports that we correctly assess the condition of a conservatory and advise accordingly.


What is an orangery?

Homeowners will sometimes refer to their “orangery”.   A good working definition is that orangery is generally a brick structure with a lantern roof.


Condition and defects

The key questions as regards condition are:

  • Is it performing its function?
  • Are repairs major or minor?
  • Is repair reasonable or is it reaching the end of its life?


1. Structural movement

There are two common structural failures: differential settlement, and rotation away from the building.

Differential settlement will generally show as misalignment of brickwork along a movement joint, usually accompanied by a vertical crack internally. The crack width with be roughly constant throughout its height.

Rotation away from the building will generally show as a tapered crack which is wider at the top than at the bottom. There may also be cracking to the floor slab (more readily seen If the floor is tiled).


2. Quality of foundation

The foundation may be shallow compared to the main building because conservatories are light structures. Some less reputable builders will build off patios.


3. Opening into main house

Some conservatories will be open to the main house. In practice, that will usually mean a lot of heat loss and considerable noise when raining. As a buyer, you need to assess how useful the room is likely to be.

Kitchens open to conservatories can cause difficulties with ventilation and fire escape depending on how they are laid out.


4. Access difficulties over the conservatory

How easy is it to gain access for window cleaning, redecoration, or roof repair?


5. Built over drains

Homeowners must have approval from their local sewerage company prior to building over a drain.

If the water supplier or local authority need to access or carry out maintenance on a drain, and a conservatory has been built without approval, then they have the authority to remove the conservatory without permission.


6. Roof condition and leaks

Polycarbonate roofs discolour over time and move within the frames. This roof needs replacement. This was seen by a surveyor inspecting from a ladder.

It is common to see gaps in the roof. The roof below will leak.


7. Misting

Just as for the double- glazed windows in the house, seals will fail and misting will occur. Panes can be replaced but this can be costly.


8. Distortion of plastic

Conservatories can get very hot, as we have all experienced. Over time, this causes distortion.


9. Hinges and handles

Do the windows function correctly? Replacing handles is a quick DIY job but replacing hinges can be awkward, especially if the conservatory has distorted.


10. Roof replacement

We are now seeing companies offering lightweight roof replacement systems. These are of variable quality and need a close look on site.


11. Roof overcladding

What sounds like a ‘quick fix’ that will save money, is actually an incredibly dangerous building practice. Often conservatory clad overs will end up costing more, in the long run, to put it right. This is because conservatory clad overs precariously weaken the conservatory structure, whilst impairing its essential ventilation elements.

The method of installing a conservatory clad over typically follows this process:

  • Drilling into the conservatory glazing bars
  • Adding extra insulation
  • Fixing timber to the glazing bars
  • Adding a thermal quilt
  • Adding PVC cladding

This technique involves many risks, most notably:

  • Conservatory roof collapse
  • Increased fire hazards
  • Increased chance of condensation, damp and mould
  • Leaks
  • Guarantee and warranty invalidation

If work looks suspect, it probably is. Our surveyors can spot the signs of poor work and will advise you in the level 2 or level 3 survey report.


Planning and building regulations


Permitted development

The owner may not have to apply for building regulations approval if the conservatory:

  • Is smaller than 30 square metres.
  • Is separated from the home.
  • Has its own separate heating system.


Planning permission

information and diagrams taken from Everest website  Conservatory | Classic & Modern Conservatories | Everest

Conservatories need planning permission if:

  1. They are higher than the highest point of the roof
  2. The eaves and ridge height are higher than the existing house (single-storey and two-storey)
  3. The eaves height is more than 3 metres, if within 2 metres of the boundary

Conservatories built to the side need planning if:

  1. They are more than single-storey or over 4 metres
  2. They are wider than half the width of the 'original house'

Conservatories built to the rear need planning if:

  1. They extend beyond the rear of the 'original house by over 6 metres (semi) or 8 metres (detached house)*
  2. They are more than 4 metres in height

Author: Richard Ballam, Regional Director


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