Saving The West Boathouse
This article is an abridged version of Practice Notes published in the Royal Institute of Architects Scotland, by Rebecca Cadie of ARPL Architects. Here, she explores some of the technical, logistical and financial challenges of restoring and repairing an unusual and complex historic building.
Background
The Category B Listed West Boathouse was constructed in 1905 as a semi-detached clubhouse for Clydesdale and Clyde Amateur Rowing Clubs, (established 1856 and 1865 respectively) and owned by Glasgow City Council (GCC). The building was listed in 1993 on the basis of its architectural and heritage significance:
- It is one of only two listed rowing club boathouses in Scotland
- It is one of a very small number of substantial timber-framed buildings in Scotland
- It is of a dignified and sophisticated design that is also pragmatic and efficient, reflecting its architecturally distinguished context in Glasgow’s oldest public park, and designed by one of Glasgow's most prolific architects, A. B. McDonald.
- It had remained substantially unaltered, with original building fabric, since it opened in 1905
- It had remained in continuous rowing use for the two clubs for whom it was constructed in 1905
By the late 1990s, the building had decayed considerably, and GCC was increasingly concerned for the safety of the building (and its occupants). Historically, the clubs had carried out their own ad hoc repairs, but by this point, the building faced serious structural issues - the timber foundations were rotting, the roof and windows leaked, the exterior render was collapsing, and the facilities were outdated and unhygienic.
Several options were explored over the next decade, including a proposal for a new 'super boathouse' to replace the East Boathouse at the opposite end of Glasgow Green. Thankfully, this plan was never realised, but it took another ten years for a new plan to develop.
Development Phase
In 2017, on the back of two feasibility and design studies, Glasgow Building Preservation Trust (GBPT) secured funding in principle from Historic Environment Scotland and the National Lottery Heritage Fund and appointed ARPL Architects to the project. The capital works proposed were:
Adaptations
- Removal of the internal party-wall to open up spaces, consolidate circulation and create shared accommodation and facilities.
- Make the building accessible for all users, with a central protected stair and lift enclosure providing access to the upper floor with accessible facilities.
- Compliance with fire regulations for means of escape from the upper floor
Enhancing the environmental performance of the building with an efficient service installation and an insulated envelope. - External works include pontoons to enable improved access to the river, and alterations to the perimeter fencing for improved safety on the riverbank.
Conservation Repairs
- Replacement of timber piles and sub-structure with concrete piles and ground beams to future-proof the timber superstructure from riverbank subsidence.
- Repairs to the unique timber structure.
- Replacing non-original masonry and render cladding with a lightweight flexible render and reinstating the original quoin details, lost since 1914.
- Replacing non-original ‘courtrai’ roof tiles with new clay ties to match original details.
- Repairing original timber windows and doors, with a few replacements on a like-for-like basis.
Making old buildings fit for purpose while remaining true to their origins is a balancing act and involves extensive consultation with building users, heritage bodies, regulatory authorities and the design team. Archival sources - old photos, architectural drawings, the rowing club’s minute books and the 1904 Bill of Works - helped build a picture of the original construction techniques and materials. Over the next 18 months, this research, along with other specialist investigations looking at timber decay, site investigations and surveys, ecology and hydrology informed a sensitive repair, restoration, and reuse scheme, overseen by Advanced Level Conservation Accredited architect Rebecca Cadie of ARPL Architects.
The project development programme of 18 months was to allow for the fabric investigations and analysis, defining the brief with the rowing clubs, and preparation of the detailed scheme and technical design. To be able to fully commit grants, funders required that planning and building regulation consents were secured. During the same period, a series of consultation workshops with the rowing clubs and other interested groups took place. Updated budget costings were prepared at several points to assist GBPT with fundraising and to ensure the budgeted finances would be as robust as possible prior to starting a contract tender process.
Site Investigations
The extent of decay of the original fabric had been assessed at the feasibility stage and a programme of localised destructive investigation was organised to confirm specific issues and details. The lack of maintenance in the last 20 years had contributed to the decay process and the potential for retention and salvage was at a critical point.
The specialist investigations were assisted by rowing club volunteers to measure water depths for the pontoon and emptying the boat stores for a day of interior timber assessment. The most significant analysis of the condition was a sub-structure survey by the architect and structural engineer with trial pits at the base of the timber frame. This confirmed that of the 30 original timber piles, there were only 2 piles with sound timber remaining, and the state of the building was precarious.
Our trust in the stability of the frame was quite dramatically tested when a sluice gate on the tidal weir jammed in August 2017. Water levels dropped dramatically (around 2 m below the usual height at low tide). Remarkably the building only suffered very minor movement, recorded with tell-tales, on the already cracked external render. In contrast, the modern concrete walkway on the opposite bank of the river collapsed due to the sudden change in groundwater levels.
Post-event analysis suggested that the frame was distributing load on the perimeter ground beam with transfer through the timber pile remnants, despite their condition, with bearing below the tidal water table. We realised that some movement tolerance would be needed within the repaired structure and finishes to accommodate a similar event in the future. This informed the decision to utilise an insulated external cladding which could reduce thermal movement and have some flexibility with a silicone render system, rather than a traditional lime harl render, which would have been too brittle and prone to cracking for the location.
Montage of the exposed timber frame in the ground floor boatbay.
Defining the Brief
The programme allowed time for a series of briefing workshops with the rowing club members and opportunities for experiencing how rowers used the building through regular activity and on race days when visiting clubs would join them. These workshops defined and established the project brief and helped build the working relationship with the two clubs coming together in a shared facility.
The priorities for the rowers were:
- The boat-store racking system and capacity to accommodate as many boats as possible, and to combine the two boat stores to have a space long enough to rack an 8-person boat without dismantling it,
- safe access to the river with the provision of a pontoon as an alternative to using the traditional timber steps for getting a boat onto the water, allowing the sport and participation to be more inclusive
- An equal and accessible distribution of comfortable changing, shower and toilet facilities, as the original conditions were basic, unsanitary and lacking in privacy, particularly for the female members. The demographics of the clubs have changed from male-only to a 50/50 gender balance in contemporary membership.
- Comfortable gyms and social areas with flexibility for a wide range of club activities and opportunities for others to book the spaces for classes or events, as an opportunity for income generation.
- Accessibility for those with disabilities was greatly restricted with narrow entrance space and steep stairs to the facilities at first floor. Re-modelling of the entrance and stair core with a lift provision would enable everyone to participate in the club community.
- The spectator viewing on regatta days was restricted due to the unsafe condition of the two timber balconies. Repair and reinstatement was considered essential for support and enjoyment of events
Design Development
Upgrade of facilities to meet the club's needs and compliance with building regulations, while retaining the original timber building and architectural features to satisfy the conservation criteria for the building’s heritage, required negotiation and balancing of priorities. The pragmatic view of the Building Control officer was a most helpful contribution to this, in accepting the project as an alteration project, and as much improvement as possible towards current Standards was encouraged, but acknowledged that full compliance could not be achieved with the retention of original structure and fabric.
With pre-application visits and discussions with the planners and building control team, the most complex issue to resolve was how to provide an acceptable fire escape from the first-floor facilities. An option of new external escape stairs was rejected in favour of a single, fully compliant, non-combustible stair within a protected zone at the core of the building.
Planning, Listed Building consent and the main funders required very detailed specifications and evidence of the research for the methods of repair, selection of new materials and matching to original finishes and colours. With the site investigations and research of the original construction drawings and bill of quantities, the Conservation Plan and analysis of use and need, this convincingly supported the developed design scheme proposals for the repair and alteration of the building. Minor areas of alteration of the external envelope were approved for the glazed entrance lobby and improved river viewing through additional windows on the first floor South elevation.
Negotiating a scheme of work that suited all parties to achieve a successful rejuvenation was a challenge to implement, and three aspects of contemporary construction and alteration were required:
- Replacement of the timber piles, without dismantling the original frame structure, was achieved with a system of concrete mini piles and concrete ground beams, which also allowed a reinstatement of original ground floor levels in the boat-store to help with boat storage capacity and improved access to the river.
- The external wall frame had lost the original harling on lath, and been re-clad at least twice with heavy cement render, except at the eyebrow gables on the South elevation which were cracked and decayed but gave us a sample of the original render for analysis. Reducing the load on the timber frame which had areas of wet rot damage, particularly at ground level, was essential and a Structherm system of external caged insulation with a lightweight silicone render was proposed to give a more stable thermal envelope to the building frame.
- The main design alteration of the layout was the removal of the central wall dividing the clubs and timber stairs, to provide an accessible entrance with a non-combustible single stair and a platform lift, within a protected escape zone. Provision of modern toilet and changing facilities have been greatly improved on the basis of gender neutrality, and the flexibility increases the accessibility the facility can offer. Moving the toilet accommodation allowed the two clubrooms to be combined and the South elevation design to incorporate the new windows for increased viewing of rowing activity.
- Retention of the original timber structure and boarded ceiling and wall linings was an important aspect of the heritage and now has improved protection with a fire detection system and formation of the protected escape zone. Thermal performance has been improved with the insulated external walls and a heated first-floor zone created with loft and floor insulation. Due to the retention of the large original single-glazed windows, the overall thermal performance of the building is below current standards, however, the energy performance has greatly improved with the renewal of services with efficiency controls and LED lighting.
Proposed Ground Floor Plan
- removal of club dividing wall and formation of central protected core
Proposed First Floor Plan
- removal of club dividing wall and creation of central protected core, remodelling of club room and changing room facilities
Rejuvenated Plan Arrangement
- The maximum space provided as ground floor boat store with boatyard and access each side
- Fully accessible main entrance from the park with direct access to wet room and changing and toilet
- Protected core for circulation and fire escape with single stair and a platform lift
- First-floor gender-neutral changing facilities and toilets
- Direct access to the enlarged club room with kitchen area
- Retention of two original gyms, the west gym dedicated to fitness and training and the east is flexible for fitness and social activities
- Access to two spectator balconies on river elevation
- Loft space floored out to accomodate plant and services and original roof timber ventilators in use
- Access to the river utilising existing timber steps and the new pontoon
Pontoon Design
Several funders had been attracted to the project making rowing a more accessible sport, through the provision of a new pontoon for safer and easier access to the river. Glasgow City Council were also supportive and agreed to an extended area of the lease grounds to accommodate a full-length “8” boat in the east yard and a controlled access gangway to the pontoon.
The installation of a pontoon on the River Clyde required specialist design work to suit the needs of river rowing boats that sit very low in the water. Although the pontoon is positioned above the weir, it will still be affected by varying tidal water heights and strong current flow and volume at times of the year when rainfall is high. This resulted in a design with a hinged gangway and landing stage and a pontoon moored with two river piles, tall enough to cope with high water levels.
Approval of the installation of the pontoon required planning consent and a Marine Licence from the Crown Estates through the Scottish Government. Consultations on the application included the GCC parks department, other river users and in particular the views of the Glasgow Humane Society were sought as the established life-saving organisation on the river, whose base is 500m upriver from the boathouse.
Tendering and Contract
As with the normal project programme for a project substantially funded by HES and NLHF, a full review of the development stage takes place on the second stage grant application.
During this period, the design team and client prepared a two-stage PQQ process for selecting suitable contractors, and the QS team prepared a tender document package to be ready for the grant approval instruction. The issue of the PQQ took place in the Spring of 2019 with the intention of a site start in early autumn of 2019. However, time was required to finalise some value engineering to the tendered proposals and for GBPT to draw the full funding package together. This hiatus on the construction project was also a necessary time for the development of the legal agreements with Glasgow City Council between the client parties for the transfer of the lease to GBPT for the construction phase and then to return to the long-term lease holding by the rowing clubs for the rejuvenated building. This also included organising the process for the assignation of design warranties at completion.
Pre-contract preparations started in the late autumn of 2019 with a contract appointment to be made for a site start in early 2020 with W H Kirkwood Ltd. However minor delays to the contract acceptance resulted in the whole programme being halted by the countrywide lockdown for the COVID-19 pandemic. Thankfully, a site start had not been made, however, the rowing clubs had cleared the building and all the heritage items taken away for archiving and conservation work and they had set up temporary storage and a base for boats and rowing activity.
The pandemic delayed the tender acceptance and placing of the £1.7million contract by a full year. Contract discussion and negotiation took place during the autumn of 2020, and it was agreed by the contractor and with support from the principal funders, that the tendered contract figure would stand as submitted with an additional provisional sum of £10k included to allow for cost flexibility due to post lockdown issues, such as materials shortage and increased PPE requirements. Site works eventually commenced on 1st February 2021 with a 57-week contract period to be complete by 4th March 2022.
Construction and Delivery Stage
Despite the careful investigations and preparation work, the progress of the work on site was not without surprises and challenges, including the Covid pandemic limitations, post-Brexit issues and the Ukraine war and their combined impact on the availability of workforce and materials and subsequent inflation in costs.
Foundations
The first significant event came after load testing the mini–concrete piling installation of clusters of 3 piles on each intersection of the ground beams. It was found that the bearing of the sand-bar ground conditions did not give the expected resistance values for the static load. The solution was straightforward in that additional piles could be added to the clusters, however, the pile caps had to be enlarged. Most steel in the UK is produced and imported from Ukraine or Russia and the war had just started causing a national shortage of supply of the additional steel reinforcement required. Waiting for the delivery of steel brought the whole project to a halt for a couple of months. Given that the structural loading of the building while in disrepair was so critical, no other work affecting building weight could take place, and only timber repairs to the roof and first-floor structure could continue.
An interior load-bearing scaffold was required for the repair of the base of the frame and a laser level kept a constant recording through the entire process of structural repairs. The repair of the timber frame was assessed on a member-by-member basis to minimise the loss of original fabric and only rotten pieces were cut out, resulting in splicing, resin and sandwich types of repair. The base of the central columns all had extensive rot or complete loss of timber where they had been in contact with the ground and each has been cut to a level of sound timber and a galvanised steel shoe fitted with connection to the ground beam. The extent of the repair was carefully recorded and can be seen in the boat store, giving the story of the work carried out.
Further evidence of original decoration was revealed and played an important contribution to the on-going discussion with the rowing clubs about the colour scheme for a building where there is conflict between their club colours being two different shades of blue and the original decoration scheme being based on Glasgow Corporation green. Through comparison of the green paint in various locations and discussion with the HES district architect, we agreed that there was a historic lack of consistency in the shade of green used and a very acceptable decision was reached that much of the original colouring was a teal colour.
Reuse / Recycle
All existing materials were carefully set aside for review of condition and potential for re-use or reinstatement with the original timber lining boards and joinery being taken for paint stripping to allow for confirmation of re-use or repairs required. Items that did not have an apparent use were set aside until an opportunity arose, such as the reuse of the stair strings for shelving in the clubroom and stair treads for a workbench in the boat store.
Assessment of the external joinery found that the carved jettied supports to the balconies all required sectional splicing. This presented complications as the original timbers are pitch pine which can now only be supplied by a few sawmills on the east coast of the USA, but they had closed down production for the pandemic period and all stock was exhausted. The engineer assessed the strength and durability of other pine species
Original windows were found to be in better condition than expected after the removal of many layers of paint, and much of the original interior board linings were stripped of paint and sound sections kept for re-use, along with the stair timber balustrading and handrail re-used on the new stair. The original timber stair sections have been re-purposed for several interior fittings.
The second significant issue that affected the project programme and costs, was the supply and installation of the Structherm insulated render system. During the development stage, Structherm was closely involved with working out installation details. Replicating the original render profiles cannot be achieved with modern lightweight silicone renders and the solution was to use resin-cast BuildLite profile sections mounted as modelled features onto the main silicone rendered wall finish.
The installation of the caged insulation and application of the render was to be carried out by a company licenced by Structherm. However, in the period from the project tender to the time of site work, the number of experienced renderers in the central belt of Scotland had diminished from 300 to 30 due to Brexit, as many of them returned to their home countries.
The remaining companies were dealing with a large post-pandemic backlog of schools and public projects. The intended sub-contractor would not hold to the tender price, re-pricing with a 300% markup on a package that was already costing over £120k. The main contractor was asked to try and source an alternative sub-contractor and price and a start on the external finishes was pushed back on the contract while other works continued. The situation was eventually resolved with the main contractor buying materials directly and employing a small team of experienced renderers who were supervised by Structherm.
Finances
COVID delayed the start of construction by almost a year until February 2021 and some fluctuation in costs was expected.
The rise of material and labour costs involved has been a significant issue for managing a contract on a limited budget, despite very diligent work by the contractor and design team to mitigate costs, and searching for acceptable economies. Thankfully, GBPT as an experienced client, was able to negotiate with the major grant funders, and due to the unprecedented complications, additional funding was awarded to meet the final account valuation of £2.1m.
Before and After
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