Making alterations to your property

Houses and blocks of flats on St Mary’s Island are subject to restrictions on extensions, outbuildings, alterations and external additions.

Trees or plants that form part of the original landscaping should not be removed.  Trust consent is required for any such changes.

These restrictions stem from the following:

  • Restrictive Covenants applying to St Mary’s Island residential property. Where permitted in accordance with policy guidance, such changes will require written consent from Chatham Maritime Trust
  • Planning requirements – St Mary’s Island is excluded from the General Development Order provisions which usually permit minor alterations without consent. Most changes will require planning consent from Medway Council
  • Building Regulation approval may also be required from Medway Council for significant or structural construction work

It is important that any such construction works have the necessary consents from both Chatham Maritime Trust and Medway Council. All development on St Mary’s Island requires planning permission and consent form Chatham Maritime Trust.  The absence of necessary consents may affect the value of your property, and your ability to sell it.  If you do not get permission before you carry out any works, subject to the covenants, you will be in breach.

In the event that you wish to change sofits and fascias, i.e. replaced on an identical basis (like for like in design and colour) then consent from the Trust is not required but you should inform us so that the information can be logged onto the property file.

If you wish to change your windows on a like for like basis from wood to UPVC then the Trust’s consent is required.  If you wish to change the size of your windows then not only do you require Trust consent but you will need to make a planning application to Medway Council; this normally takes in the region of 6/8 weeks.

If you wish to install a garden tap please note that planning permission is not required from Medway Council.

There is no guarantee that retrospective planning or covenant consent will be forthcoming, and in any event a retrospective application is likely to cause significant delay in the property sale process.

Effective mid January 2018 a new planning application fee rule has been introduced which increases Medway Council’s planning fee but more specifically to note is that a planning fee will now be required where permitted development rights have been removed, i.e. St. Mary’s Island.

Previously applications for things like sheds did not require a fee to be paid (if planning permission was only required because the permitted development rights have been taken away).  This is no longer the case as of mid January 2018.

Medway Council aim to determine planning applications within 8 weeks for minor applications and 13 weeks for major applications.

For guidance and information on Medway Council’s Planning Process or visit

Consent Applications to the Trust

Chatham Maritime Trust’s policy will generally, though not always, align with Medway Council’s planning policy / decisions. Trust consent will not be forthcoming for any application refused by Medway Council.  See Medway Council Planning Portal.

Trust staff are willing to have a brief informal discussion over resident proposals. Please make an appointment to come into the Estate Office and bring as much information as possible.

Residents will need to make a formal application to the Trust, and this must be accompanied by a (non-refundable) fee.  There is no application form to complete; applications can be submitted in written format to the Trust office or emailed with comprehensive information to .

Applications to the Trust for consent under the restrictive covenants should include:

  • A written description of the proposal including external dimensions and proposed finishes.
  • For extensions, conservatories, and other significant building works: two copies of professionally-produced drawings
  • For outbuildings, external fixtures etc: Plans (a copy of the conveyance plan or an Ordnance Survey extract) or elevations (if the latter, photographs will suffice) showing the proposed location
  • A copy of any planning consent from Medway Council (if obtained) or a copy of the planning application
  • Payment of the appropriate fee

If the application is approved, the Trust will issue a formal letter of consent. This should be kept with the property deeds as it will be required for an onward sale of the property.

Retrospective Applications

The Trust will consider retrospective applications for work already carried out; there is no guarantee that consent will be given. Relying on restrospective planning consent may delay the sale of your property.


Chatham Maritime Trust Charges Fees for a variety of consents and certificates required under the terms of the St Mary’s Island Rentcharge Deeds.

Important Note:

All properties on St Mary’s Island have been constructed with piled foundations due to ground conditions. It is therefore essential that residents considering any extensions (inc. conservatories) take appropriate advice on foundation design.

This is the homeowner’s responsibility and the Trust can offer no advice on or approval of specific foundation design.

The Trust does not recommend any contractors or consultants. Residents seeking advice may wish to contact:

The Institution of Structural Engineers
11 Upper Belgrave Street
London SW1X 8BH
Tel.: 0207 235 4535

Or visit

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