Architect's Design Statement

Architect's Design Statement

Proposal: External works to a Registered Building (RB. No.37) The Site: 7 The Parade, Castletown, Isle of Man IM9 1LG Applicant: Mr. & Mrs. N. Arculus

Contents

• 1.0 Condition of the exterior of the building
• 2.0 Recent Planning History
• 3.0 Planning Considerations & Pre-application Advice
• 4.0 Proposed External Works
• 5.0 Conditions of Approval

Appendices

• Appendix I - Archive Photograph
• Appendix II - Exterior photographs

1.0 Condition of the Exterior of Building

The property is a Registered Building which is situated in the main square in Castletown, adjacent to the Co-operative store. A full building conditions survey has recently been undertaken by Steven Morley, Chartered Surveyors, prior to the applicant purchasing the property.

The external walls are of solid masonry construction in limestone. The walls were originally rendered, as illustrated in the archive photograph shown in Appendix I, however the render has at some time in the past been removed and the stonework left exposed. The joints were re-pointed using inappropriate cement mortar.

The pitched roof has a slate finish with a stone parapet/verge detail along the south east gable. The parapet has no damp proof course. The gutters to the front and rear of the property are lead lined box gutters with a sandstone coping detail to the top of the wall. The lead to the gutters is cracked in areas and requires replacing. The joints between the sandstone coping appear to have been inappropriately filled/repaired with mastic. The main rainwater pipes to the front and rear elevations are cast iron with a rainwater hopper to the rear elevation which appears undersized for the size of roof.

There are modern rooflights on each of the front and rear roof elevations. These replaced the original rooflights but are small and provide no opportunity for emergency escape from the upper floor.

The chimney stack is exposed limestone with cement mortar. The stack has had a concrete coping installed in the past to replace the original sandstone coping. The condition of the chimney pots and flaunching can not be ascertained at this stage. Lead flashings and soakers have been installed to the base of the stack but appear to be a retro-fit and are to be reviewed when scaffolding has been erected.

Due to the removal of the existing render and use of inappropriate cement mortar together with the other inherent problems as described, the interior of the building, especially the exposed south east gable, is suffering from severe damp penetration. Work has been undertaken at some point in the past to conceal the problem by internally lining the gable wall, however damp penetration is still evident. This has affected the internal decorations as well as causing problems in some of the timberwork.

Damp penetration is predominantly from:-

• Exposed solid wall construction and use of inappropriate cement mortar to the joints.
• Inherent defects with a lack of a damp proof course and poor flashing detail to the chimney stack.
• Lack of damp proof course to the upstand parapet/verge detail.
• Cracked lead to gutters and blocked rainwater outlets.
• Gaps to the window surrounds and below the window cills.

2.0 Recent Planning History

09/01920/GB \& 09/01921/CON - Installation of replacement windows to the rear elevation. The application was for replacement timber sash windows, and was permitted in 2010. The work was undertaken and completed.

3.0 Planning Considerations \& Pre-application Advice

Apart from the historical photograph, it is evident that the original building was intended to have a rendered finish, and detailed so that it would have an appropriate status within the main square. While the exposed stonework is of a reasonable quality, the slim nature of the stone lintels over the windows and doors suggest they were never intended to be left exposed. Over the basement windows there are double lintels with infill stone between which again suggests they were never intended to be exposed.

The building has presumably suffered from damp in the past which would have caused damage to the original lime render. This has been removed and the decision made to leave the stonework exposed and re-point with inappropriate cement mortar which does not allow the stonework to breathe or damp to escape from the structure.

The proposal is to reinstate the building to as near its original appearance as possible and to render the front and gable elevation in a hydraulic lime mortar. The lower section of the front elevation will have the original rusticated render detail reinstated. This will have a fairly shallow recess as per the archive photograph rather than the deeper recess evident on other buildings in the area.

The archive photograph shows that the render to the upper floor had an etched or ruled line to give the appearance of stone coursing. However, it is our intention to retain the raised band detail around the window openings and to omit the etched line as it is felt that the quality of this etched detail has been achieved with varying levels of success around Castletown. The proposal is to provide a smooth rendered finish to the upper floor and the gable elevation which matches the finish of the neighbouring property, Balcony House, which is a Registered Building and has also undergone renovation in recent years.

The proposals has been discussed in detail with the Conservation Officer, who has also carried out his own research into the original appearance of the building. The discussions have been productive and overall the scheme as proposed has received a favourable response.

4.0 Proposed External Works

External repairs and remedial works are to be carried out in order to overcome the issues of damp penetration into the building and there by provide the occupants with suitable dry living conditions as well as protect the structure and internal finishes of this Registered Building. The proposed works are as per the following specification and are to be carried out by Grenaby Limeworks Ltd who are proficient in such work.

1. South East (Gable) Elevation. Remove the existing cement pointing and render the whole elevation with a hydraulic lime mortar with a flat trowel finish. Drip edges to be created as shown on the elevations.
2. North East (Front) Elevation - First Floor. Remove the existing cement pointing and re-instate a flat render finish in hydraulic lime mortar including the rendered bands at first floor and to the window surrounds.
3. North East (Front) Elevation - Ground Floor/Basement. Remove the existing cement pointing and re-instate a rusticated period finish in hydraulic lime mortar to match the detail of the original building. Horizontal banding to be formed with a V-shaped recess at approximately 300 mm centres. A simple lintel detail to be provided over the door and windows openings to match the archive photograph. A sample panel can be provided prior to carrying out the work for approval by the Conservation Officer.
4. South West (Rear) Elevation: Remove the existing cement pointing and re-point with a hydraulic lime mortar. The existing cement render to the window reveals to be removed and the reveals re-rendered with a hydraulic lime mortar.
5. Chimney stack. Remove the existing cement pointing and re-instate a Hydraulic lime render around the stack. The chimney pots are to be checked and the cement bedding/flaunching made good as necessary. The pots are to be fitted with suitable terracotta ventilated 'mushroom' cowls, subject to the style being confirmed and agreed with the Conservation Officer. New code 4 lead flashing to be provided at the abutment with the slate roof.
6. Chimney Coping. The original sandstone coping to the chimney stack has been replaced/modified using a heavy cast concrete coping. The condition of the coping to be examined when the contractor has scaffolding access. Depending on the condition the coping may be replaced with new. If this is the case then the profile and detail will be agreed with the Conservation Officer.
7. Parapet/Verge details. The existing sandstone coping is to be removed and the top of the parapet wall is to be made good with a hydraulic lime render ready to receive a lead strip damp proof course. The sandstone coping is to be re-bedded on the new lead DPC. New code 4 lead flashing to be provided at the abutment with the roof and lapped up and bonded to the DPC to fully encapsulate the parapet wall along the junction with the roof.
8. Gutters. The sandstone gutters to the front and rear elevations are to be re-lined with code 4 lead. The lead is to be taken up sufficiently below the roofing slates to allow for wind driven rain and the possibility that there may be over shooting of water at times due to the narrow width of the gutter. The joints between the sandstone sections have been repaired in the past with what appears to be mastic. The mastic and joints are to be raked out as much as possible without damaging the sandstone and the joints filled and repaired as necessary with 'Lithomex' stone repair mortar to match the sandstone finish.
9. Rainwater goods. The existing cast iron rainwater goods to the front and rear elevation are to be refixed following the re-pointing and rendering works. The cast iron rainwater hopper on the rear elevation appears to be undersized and is to be replaced with a new larger cast iron hopper of similar style.
10. Rooflight. The existing modern rooflights to the front and rear roof elevations to be replaced with new Velux Conservation roof lights (Size: ).

5.0 Conditions of Approval

As part of the Planning Approval or Registered Building Consent we would have no objection to any conditions requiring samples of materials or finishes to be provided for approval by the Conservation Officer prior to the work commencing.

When scaffolding has been erected a closer inspection of parapet walls, gutter etc can be carried out. Any modifications necessary to the proposed works, as detailed in this document, will be reported to the Conservation Officer to seek his advice and confirm that the works are still compliant with the Planning Approval and Registered Building Consent.