Building in harmony

Located midway between the two bridges on the south bank of the river, the regional music centre has become a recognised landmark long before it is due to open. Reaching 42 m at its tallest point, it stretches higher than the Tyne Bridge and is based over seven levels, which gradually decline in size as the ground slopes towards the river. "It's an unusual shape, it's in a prominent position, you can see it from everywhere, and people are going to talk about it," stresses Ray Henderson, project manager with m&e contractor Haden Young.

The £70 million structure was designed by architect Foster and Partners. It will bring classical, folk and jazz music lovers together under one roof. It will also house a music school, nurturing young talent, and a regional music information service. These combinations explain in part the unusual, flowing shape of the building and have meant specialist techniques have been needed to allow different types of music event to be heard at their best and simultaneously.

The steel-clad roof cloaks three adjacent buildings: a large rehearsal hall flanked by a 1650-seat auditorium and a 400-seat hall. The larger auditorium is more traditional in style and is designed for acoustic perfection. This will provide a home for top classical group Northern Sinfonia, as well as other large-scale performances. The smaller hall provides a more intimate feel. A ten-sided room with a central, moveable stage, this is designed for flexibility of use and will see founding partner Folkworks perform.

The three lumps in the roof roughly outline the individual halls. Its bulbous shape provides space on the river-facing side for a spectacular public concourse; and on the opposing side for back of house services and plantrooms.

"The biggest challenge [on this project] was the acoustics," stresses Henderson, "making sure that we complied with the specifications with regards to vibration noise concession." These specifications begin with the structure, it being vital that the audience in one hall cannot hear the activities in the one alongside. Henderson explains: "There are acoustic joints between [the halls] so they can move and any vibration or noise can't transfer across." The roof floats above the buildings, sealed at the external edges by special, flexible joints to prevent heat loss, while enabling it to expand and contract with temperature changes without affecting the acoustics.

A warren of assorted practice and teaching rooms fill the lower levels of the centre. Again, acoustic sensitivity is everything, hence the areas are formed using a box-in-box construction. The room floors sit on springs and acoustic gaps and specialist fixings abound.

This attention to detail and high specifications meant it was vital that the m&e contractor's methods of installation were finely honed. It may have been possible to construct the buildings so that they will never touch, but getting even the most basic of m&e services into a room means that an acoustic barrier must be crossed, and the services here are far from basic. Specialist electronic and theatre products abound and over 100 000 m of sound and communications cable spider the site.

"Every time we penetrate one of those [acoustic joints] we've got special details for pipework, cables and containment," explains Henderson. "We can't have any noise transmission." The solutions have been considered in minute detail – every item involved in every area of the building has been considered and a method to eradicate vibration found.

Where cable basket passes through an acoustic joint, it is broken in two and a flexible material used to join the parts so that there is no metal-to-metal contact at the joint. "Even the trunking where the cables pass through has flexible connectors," stresses Henderson.

Splitting the pipework as it spreads across the areas was unfeasible: the solution here was to hang it on springs, spaced at calculated distances to remove any vibrations. These springs were sized and colour-coded, being preloaded to suit the specific mass they will hold.

As well as ensuring the distribution networks were vibration-free, Haden Young had to make sure that the m&e equipment in the 12 plantrooms scattered throughout the site met the required specifications – no mean task. "All the plantrooms are different but they all have the same principles," explains Henderson.

All pumps sit on inertia bases, which are basically a concrete-filled, metal-frame, mounted on anti-vibration mountings that cushion start-up motion. Large plant such as air handling units and boilers are mounted on Piramat which, to the untrained eye, resembles a squashy bar of segmented chocolate. It was not just a case of placing the equipment on the Piramat; more calculations were needed as Henderson explains: "You have to work out the weight of each machine and how much you need to depress [the Piramat] by to make it function to work out how many [segments] you need...if it's all depressed, that's inefficient."

It was Haden Young's, and specifically Henderson's, responsibility to ensure the correct detailing, amount of cushioning and spring sizes were applied in each situation. "There are lots of different scenarios you go through when building the job. It's particularly challenging to ensure you get the right kit to the right place for the right detail and physically make sure that it happens on site.

"There were a lot of instances where we've had to work with the design team to come up with solutions to satisfy the acoustics."

The installation details were so complex in some areas of the project that Haden Young held supervised workshops for operatives as they began on site rather than them simply being issued with drawings.

The installation was electrically more complex than mechanically due to the production sound and lighting systems. The majority of the mechanical services installation involved air systems and underfloor heating, which covers the vast areas of floor in the public concourse and music school levels.

In the auditoriums, electrical supplies feed from roof and floor levels to satisfy the vast array of equipment to be served. The cabling for the down feeds are controlled on Mercaddy wheels, which wind the cables in and out on a pulley system as equipment is raised and lowered, avoiding any potential tangling or safety risks.

  In the open concourse area, aesthetics were vital. Speakers and lights have been confined in the main to balcony fronts. Custom-designed Onix floor boxes scattered throughout give access to the electrical power ducting as well as providing IT and data points. These also give access to custom-built panels that will be used to control special lighting effects, enabling projections onto the store-rendered walls of the buildings.

Direct connections to the roof have been limited and the small number of cabling routes here to supply cctv power supplies have been encased in galvanised steel conduit so they are undetectable to the naked eye.

Ventilation in the concourse is limited to three, automatically-controlled vents strategically positioned above the main buildings for ease of maintenance. There are also small, stand alone systems at the balcony bars and restaurants.

To control the numerous electrical systems in the centre, such as security, cctv, access control and building management, an integrated building management system has been installed.

The three main halls were constructed simultaneously, which influenced the organisation of the m&e team. Henderson explains: "We tried to treat it as three separate buildings. It made sense for us to keep teams separate, so the construction teams for each building were only dealing with one person." One mechanical and one electrical engineer was in control of each building, with operatives generally working on a single building throughout. At peak, Haden Young had around 90 operatives on site.

The team is set to complete on site in the second half of 2004, after which a three-month client fit-out period will take place before the doors open to the public.