Photos - Attachment 2 - SOW - Wychwood House BOILERS REPLACEMENT - rev04.docx

Scope of Work Boilers replacement at Wychwood House

US Embassy, London – Facility management November 2024 By LAB Rev 04 (June 2025)

CONTENTS:

ATTACHMENTS:

1. Contractor clearance form.

2. Existing boilers technical document.

3. 38 x Photographs of the Boiler Room

Site address Wychwood House 1 Cottesmore Gardens London

W8 5PR

Introduction Background and deficiency description This three-storey detached house is in The Royal Borough of Kensington and Chelsea. It was built in 1851 and enlarged in 1893. The predominant architecture is Georgian, and it is within the conservation area known as De Vere and part of the Queen’s Gate ward.

The house has an imposing modillioned pediment and is a three-storey building, seven windows wide with a fully stuccoed frontage, moulded stringcourse and quoins to the returns and central sections. It also has a blocked stucco base.

The boilers are over 14 years old and have reached the end of their working life. A replacement is proposed to include the boilers and accessory equipment as described within this scope of work.

Purpose of this document This document is issued by the US Embassy in London with the purpose to enter into a contract with a HVAC contractor with extensive experience on commercial and large residential buildings in central London to undertake the work described herein.

The Contractor shall provide all necessary managerial, administrative and direct labor personnel, and as well as all necessary transportation, equipment, tools, repair parts, supplies and materials required to perform the work described herein. The work shall be carried out in accordance with the manufacturer’s instructions for any equipment, system, product or material specified within this document.

Due to the character of this site, all the materials and the workmanship shall be of the highest quality and durability.

General requirements Health and safety, welfare and environmental procedures The contractor shall fully comply with the Construction (Design and Management) Regulations (CDM 2015).

The contractor shall provide the COR with all sites specific Risk Assessments and Method Statements after award and prior to commencement of works. Once the RAMS and all the procurement department’s requested documentation are received and deemed satisfactory the Notice to Proceed (NTP) can then be issued.

After surveying the facilities and the relevant equipment, the contractor shall inform the US Government of any health and safety concerns or special requirements so their work can be carried out safely. This information will have to be included in the contractor’s cost proposal.

It is the contractor’s responsibility to ensure that all their employees are equipped with certified safety equipment (PPE) to complete the tasks as requested within this document and provided attachments, and in accordance with the contractor’s method statements and health & safety plan.

The contractor shall request from the COR all the Embassy Health & Safety procedures to include but not be limited to egress routes, exits and assembly points in the event of an emergency.

Restrooms and welfare facilities are available for the use of the contractor at the US Government building.

The contractor shall be responsible for the safe and environmentally friendly disposal of all redundant materials, parts and consumables. Safe disposal records copies shall be provided to the Embassy after each visit.

All work shall comply with the local Health and Safety regulations in the UK. The link to the website is www.hse.gov.uk

Security requirements The US Department of State operates strict security procedures for entry into its properties. All the personnel likely to be involved on site at any time during work shall complete the security questionnaire on the attachment. This form shall be completed and submitted to the Embassy immediately after the award along with a photocopy of the employee’s current passport.

The right is reserved to refuse entry to the building at any time. Any decision on this matter shall be final and conclusive and at no additional cost to the US Department of State.

When necessary, contractor employees shall be escorted by security personnel during the performance of their work.

When escorted, a maximum number of 4 contractor employees are allowed per escort. If the contractor estimates that more than 4 employees are required or if the work needs to be done simultaneously in separate areas of the building, this needs to be notified to the Embassy at least 7 days in advance, so adequate escort resources can be mobilized.

The US Department of State reserves the right to request additional information in certain cases.

The contractor’s employees must work only within areas relevant to the equipment they are responsible for maintaining. No contractor’s personnel shall visit any other locations outside of these areas without prior approval.

Commencement of the contract No work shall commence, or equipment and materials be ordered until the contractor has received a purchase order and a NTP for the works stating the start date and the end date of the contract.

The Contractor shall designate a representative person who shall supervise the Contractor's employees and be the Contractor's liaison with the U.S. Government. The Contractor's employees shall be on-site only for contractual duties and not for any other business or purposes. Contractor employees shall have access to the relevant rooms, either with or without security escorts, only with specific permission by either the Facility Manager or the COR.

Contractor’s personnel certifications It is the contractor’s responsibility to ensure that their employees are competently qualified, trained and certified to work on all specialist equipment or materials named within this document and attachments The contractor shall proceed to provide proof of competency of all his operatives, including but not limited to, qualifications, certifications, training and experience on similar work in other locations.

Access and parking The contractor is responsible for providing the COR with operatives’ names, vehicle registration plate number, make and colour, and any other details relevant to the work on site (i.e. deliveries expected) with at least 48 hours in advance.

The contractor is advised that a maximum of one parking space is available. However, the US Government may not be able to provide parking on certain occasions.

Working hours Unless prior arranged the work shall be undertaken on weekdays (Monday to Friday) and during working hours (8am to 5pm).

Regarding local and American holidays no work shall be undertaken unless prior agreement and at no addition costs to the US Department of State. Please refer to the following web site for the US Buildings General public holidays, https://uk.usUS Government building.gov/holidays/ Standards of conduct in the premises The contractor employees shall maintain satisfactory standards of competency, conduct and cleanliness when working within a US Government property. These standards are especially strict when working within office environments or when working in or accessing adjacent areas.

The Government reserves the right to ask the contractor employee to leave the premises when the above is not complied with, or the employee is deemed disruptive. The contractor shall immediately replace such an employee to maintain continuity of services at no additional cost for the Government.

The Contractor's employees shall wear clean, tidy and complete uniforms with clear means of identification when on duty.

The contractor employees must not smoke outside the designated areas, play music in any part of the premises or use abusive or loud language at any time within the US government building boundaries.

Key control The Contractor shall not depart the building grounds whilst in possession of any keys. All keys shall be controlled and given back to the government representative prior to leaving the premises. However, if the contractor or their employees depart the building without giving keys back, the contractor may be responsible for the costs of as a minimum: gaining entry through locked doors or gates, repairs, replacing locks and providing additional keys.

Storage of materials and contractor’s tools and equipment If the work is planned to take more than one day, the contractor personnel shall store relevant materials, tools and equipment in a lockable site box to be provided by the contractor which shall be removed at the end of the service.

No contractor’s property and materials shall be left in the US Government premises after the work is completed.

Modifications to the contract This section refers to repairs, modifications and/or parts that could be required after the contract is signed.

The contractor shall supply the US Government with a formal quotation for approval before this work can be carried out.

Only those works specified in writing in the official scope of works issued with the Purchase Order/Delivery Order/Contract are to be undertaken by the Contractor. Any changes or deviation to the scope of work will be made in writing via an official modification to the original Order or Contract. Should the Contractor undertake any works not specified on the official scope of works or subsequent official modification to the scope of works, the US Government will not be liable to make payment for the additional work, all additional works will be at the Contractor’s own expense.

If during the course of the execution of the works the Contractor deems additional works, outside the original scope of works are required, they should inform the Contracting Officer or Contracting Officer’s Representative (COR) in writing, giving full details of the additional works, the reasons why they are deemed necessary and a full breakdown of any additional costs which would be incurred in undertaking the works. The Contractor should not commence any proposed works until such time as confirmation is received by the Contractor in the form of an official written modification. The Contractor will be financially liable for any works outside the scope of works undertaken by the Contractor in the absence of an official modification.

Schedule documentation required A schedule that defines the tasks to be undertaken by the contractor and the sequence of work are required. Also, a list of tools, equipment and materials being brought on site is required.

This shall be presented in the form of a Gannt chart (both MS Project and Excel are acceptable) and shall have the days horizontally and the work’s tasks vertically. A full breakdown of each task shall be included.

Specific requirements Period of performance The contractor shall complete the work described in no longer than 28 calendar days (4 weeks) from the day stated in the NTP (notice to proceed). This time includes all the surveying, sizing of the boilers, mobilization, ordering and delivering of materials, preparation, execution, commissioning and clearing and cleaning the site.

The Gantt chart shall include every task from NTP till completion and clearly identify the heating downtime (number of days with no heating) within the program.

Boilers replacement Introduction The boiler room is in the basement of the building. It holds two floor standing condensing gas boilers model FS 90 Potterton, one open vent hot water cylinder, a low loss header, a water softener, circulation pumps, valves, filters and basic controls.

The two boilers work in a master-slave configuration.

All the elements inside the boiler room shall be replaced with new ones, including the pipework re-arrangement and except the hot water cylinder, the water softener equipment which shall be set aside, cleaned, tested and re-connected.

Existing Potterton gas boilers

Preparation work and initial submittals Immediately after the NTP date, the contractor shall undertake a thorough survey of the existing installation to identify, record and undertake a full schedule of components. These shall include but not be limited to:

Boilers. Please see technical features of the existing boilers as an attachment.

Heating pipes layout and all heating system elements within the boilers’ room, including low loss header, pumps, valves, strainers, fittings, brackets, actuators, sensors, switches etc.

Gas pipe layout in the boiler room. The gas supply should be fully inspected and tested.

The flue system including its fan and sensors. To include testing.

Existing heating pumps’ head pressure and flow rate.

Housekeeping pads Electrical Power supply Controls panel Any other items that may impact on the new boiler installations, commissioning and the Gas Safe Compliance.

Include water chemical testing of the existing heating system.

Report on all findings to the Embassy’s COR and identify any issues that could prevent us from gaining a compliant Gas Safe Certificate and satisfactory commissioning at the completion of the work.

Provide the manufacturer, model and size of the proposed commercial boilers as well as of the main components (i.e. burners, etc.) to the Embassy’s COR for approval.

Provide the manufacturer, model, head pressure and flow rate of the proposed heating pumps to the Embassy’s COR for approval.

Provide the schematics of the proposed system including but not limited to boilers, hwc, water softener, valves, pumps, actuators, sensors, low loss header, filters water and gas pipes.

Disconnection work This project is expected to be executed during the summer months, where heating is unlikely to be required during long periods. The contractor shall advise of the estimated time the building will be without central heating and gain approval from the COR.

The hot water supply shall be kept operational during the duration of the project.

Safely disconnect and remove all existing equipment and pipework relevant to this scope of work from walls, floors and ceilings.

Boilers requirements To supply, deliver, install and commission two new identical boilers. These shall be manufactured by a reputable manufacturer established and with a representative based in the UK. The boilers shall:

Be floor standing.

Be compatible with the existing heating and hot water systems.

Be condensing modular type boilers.

Work in a master-slave configuration. The control system shall be able to alternate the master role between the two boilers automatically. Both boilers shall be able to work simultaneously if needed by the load requirements.

Provide a 90-kW heat output for water each (kw to be confirmed by the contractor and approved by the COR) @ 80/60 deg C each boiler.

Have the primary heat exchanger made of stainless steel, cast iron or superior material.

Be able to provide 40 deg C differential water temperature at the system design flow rate.

Be able to operate up to 90-degree Celsius maximum flow temperature.

Have a heat exchanger cell rated at 10 bar pressure rate minimum.

Be 94 % gross seasonal efficient.

Be delivered fully assembled and shall fit through the site’s doorways and corridors.

Have a noise level @ 1 meter not higher than 65 dba.

Have built-in controls platform with sequence control.

Have a control panel that controls both boilers.

Have spare parts available by a UK supplier.

The manufacturer of the burners and any other major component shall also be established and have a representative in the UK.

Be ready to be fueled by Natural Gas.

To have emission (NOx) in accordance with the British Standard / Local regulation.

To have a heat exchanger with a 10-year warranty.

The vendor shall supply two identical boilers with the pipe kit for the two boilers.

For example, as manufactured by Hamworthy, Vaillant or Worcester-Bosch or technically equivalent equipment from an established manufacturer with a representative in the UK.

Other accessories and work required.

To supply, deliver and install all the materials required to undertake all the modifications to the pipe arrangement to accommodate the new boilers.

To supply, deliver and install new flues to comply with the boilers manufacturer instructions, local building regulations and gas safe instructions. The termination of the flues outside shall include a stainless-steel cowl to avoid rainwater ingress.

To supply, deliver and install new pumps from Grundfos Pumps Ltd or technically equivalent product and as approved by the COR. The contractor shall provide a full pump schedule and the schematics indicating pump manufacturer, model, size, function and position for approval by the COR.

To supply, deliver and install all the necessary heating system components to replace existing and for a fully functioning system. The pipe kits shall include but not be limited to new strainers, filters, valves, low loss header, pipes, safety relief valves, pressure gages, temperatures gages, sensors, actuators, switches, panels, etc. within the boiler room.

To supply and install all the necessary components for an S-plan system as recommended by the boilers manufacturer.

To supply and install a magna filter to return pipe for each boiler.

To supply and install a descaler.

To remove the lagging of all the pipework, including the new low loss header. All existing pipework within the room shall be exposed for inspection by the COR. After inspection all pipework (existing and new) shall be provided with new lagging.

To undertake the re-arrangement of the gas pipe, provide a new solenoid valve and push button and all the necessary accessories to comply with the current gas safe regulations and building regulations.

To undertake flushing and chemical cleaning of the heating system. This shall be in accordance with BSRIA BG29 2021. The contractor shall incorporate the necessary elements to the system so they are able to undertake the flushing of both the new and the existing piping without running the water through the new boilers.

To clearly label all pipes and equipment with machine printed characters to indicate as a minimum: direction of flow and pipe function (CWS, HWS, heating, etc.).

Electrical Ensure that the two boilers can run independently from each other and in “hand” mode. The house operators shall be able to choose which boilers should run in the event of a boiler breakdown.

The electrical characteristics and power demand for the new boiler must not exceed that of the current boilers.

The existing power supply is not sufficient to power the hot water cylinder when this is on immersion heating mode. The contractor should upgrade the wiring to ensure the new electrical installation is adequately sized.

The electrical institution, testing and certification works shall be compliant with the latest version of BS7671.

Submittals at completion At completion the contractor shall provide a complete Operation and Maintenance Manual to include all the Legal, Building Control, Gas industry Standards and Manufacturer documents. As a minimum this shall be:

Commissioning checklist (Benchmark), Gas Safe Certificate for the boiler.

Landlord’s gas safety record.

Proof of notification to the Local Authority Building Control for Building Regulations Compliance.

Electrical certificates.

Proof of registration of both the boilers and warranties.

Letters from the respective manufacturers stating the guarantee conditions (minimum 5 years for each appliance).

Description of work undertaken.

Maintenance requirements for all new products and equipment installed.

Insurance details.

As fitted drawings.

Training details.

H&S documents.

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