City of London Freemans School

with Hawkins\Brown

Services: Consultancy, condition survey, repairs and upgrading of historic fire doors.

As the school had been using the building for many years, the school did not want to change the house significantly but following the completion of a masterplan by Hawkins\Brown proposed to move all of the clerical facilities from the house to provide enrichment facilities.

Enrichment facilities included the introduction of seminar spaces at ground floor to promote open discussion and seminar type learning experiences in contrast to the traditional teacher to classroom style arrangement. Flat style accommodation is provided for students to gain an insight to life in higher education.

Conservation philosophy

The conservation philosophy for the project was:

-        To carry out minimal alterations to the building fabric.

-        To respect both the 18th and 19th century plans removing only modern 20th century elements.

-        To carry out repairs rather than replacement of building fabric including the windows, stonework and brickwork.

-        To restore Ralli’s historic interiors based on documentary evidence

-        For new elements of building interior to be carried out in a contemporary style so not to confuse with the original scheme.

Technical challenge

The biggest technical challenge was meeting the stringent technical requirements of the City of London Building Control Department to resolve the building regulations in relation to fire protection.  

As the building had been in use as a school for 90 years, the building had grown organically. The concept of providing sleeping accommodation in the school meant that the full requirements of part B of the building regulations needed to be taken into consideration.

The house is typical of many country houses with the main house (the east wing) a three storey building and the service wing (the west wing) a two storey building. In each wing the staircases do not provide a route to a final exit, and the level of fire protection provided is arguably made worse by Ralli’s construction of the Ballroom (now dining room). Many of the doors in the house are historic and do not provide thirty minutes fire protection.

Conservation techniques employed

Specialists, the Fire surgery were engaged to provide a strategy for fire escape. The strategy proposed was to carry out the following:

-        To separate the east and west wing, so that teaching and residential uses where formally separated by compartments. Sleeping accommodation in the west wing and education uses in the east wing.

-        To provide a new staircase in each wing to improve means of escape.

-        The new staircase in the west wing providing a final route from the sleeping accommodation to outside.

-        The new staircase in the east wing providing a second escape route from second to first floor only.

-        The compartment lines were designed along the lines of the very thick historic masonry walls for the natural resilience to fire.

Fire doors

In order to save potentially damaging work to the historic fire doors, we carried out a condition survey of 111 doors on the proposed compartment lines was undertaken. The survey confirmed that most of the historic doors provided 20 minutes fire resistance, subject to repairs being carried out and the use of intumescent products could be upgraded to 30 minutes fire protection

Of the 111 historic doors surveyed only 6 of the doors could not be upgrade to meet the FD30 requirements or supplemented with additional doors that would meet that requirement.

The entrance door to the Inner Hall GFW6, see image below. The door achieves 20 minutes protection and can be upgraded with self-closers and intumescent seals and smoke strips.

The other five historic doors are from an unusual composite construction.  Further investigations were undertaken prior to tender by drilling a 3mm hole in the panels of the door to determine the panel thickness. The investigations confirmed that the doors provided 20minutes fire resistance.

Owing to the strategy implemented by the Fire Surgery, the documentary evidence of the performance of the fire doors and an enhanced fire alarm system a lesser degree of protection was agreed to the remaining 6 fire doors.

Conclusion

As a consequence of collaborative working between the design team and consultants, a scheme of minimal intervention was achieved saving the demolition and removal of a significant number of the historic fire doors (a handful were removed that we badly damaged or in order to provide the new staircase) and the retention of all of the significant fire doors.

Whilst the works involved the removal of two historic floors, the proposed plans respected the historic form of the property and detailed consideration was provided on the appearance of the stairwells as part of the pre-application discussions with the local authority conservation officer and Historic England. The design of all new alterations have been executed in a contemporary style so that new interventions are clearly discernible from historic fabric and as a result the works are an exemplary example of the sensitive execution of one of the most challenging aspects of building conservation.

james mackintosh architects limited

studio@jmackintosh.com

First Floor, 21 The High Street,

Chipping Norton, Oxfordshire
OX7 5AD

01608 692 310 / 07880 727 150