South Lodge is an extremely grand Victorian manor house, set within 90 acres of well cared for gardens and parkland, and features breath-taking views of the beautiful South Downs. The beautiful scenery and pure air create complete peace and relaxation for guests staying at this award-winning, luxury hotel – providing much needed escapism from the daily grind. The spirit of South Lodge is embodied in its exclusive, luxury Spa, which was opened in February 2019.
The Building
The Spa is a substantial, 4000 square metre building, being deliberately set into the natural contours of the land. It complements the surrounding landscape by boasting a large, 1750 square metre extensive green roof. The roof is shaped in an artistic and natural looking wave formation, with a longer flat section sloping upward to transform into the curved ‘wave’, adding a modern, dynamic feel to the building, whilst simultaneously softening it to reflect the Spa experience. The green roof was designed as a wildflower, biodiverse roof, containing a mixture of native British plants, enabling it to blend in perfectly with the surrounding parkland.
The Hotel Irrigation Project
Access Irrigation were responsible for the design and supply of the complete hotel irrigation system watering the extensive green roof. The system was fully automated, using a Heron Ma-6 irrigation controller. This controller has a large digital display for easy, accurate programming and a very high level of reliability, including featuring a permanent memory so programmes are never lost due to power failures. The controller also features a pump freeze facility, which in conjunction with a float switch will suspend the programme in the event of a failure in the water supply. To prevent operation in wet weather a rain sensor was included. The controller was also supplied with sophisticated software which allows a long delay between irrigation cycles. This delay option is ideal for extensive green roofs like this one, which are drought tolerant and only require irrigation during dry spells. A Cat 5 pump & tank unit with a Type AB air gap was used to create a pressurised water supply and to comply with the Water Regulations regarding backflow prevention. The pump was located externally, secured beside the tank – the pump & tank operating together as one unit. A Lowara Genyo pump starter was included to enable the pump to operate when there is a demand for water and also to provide dry running protection for the pump. Hunter PGV Jar Top solenoid valves were used to split the system into sperate zones, allowing each zone to operate at a separate time, thereby providing good water flow and therefore efficient watering for each zone. The valves were fitted with adjustable pressure regulators, to ensure correct operating pressure for the dripline. The solenoid valves were connected to the controller via signal cable and connected to the pump & tank unit via supply pipe.
Each solenoid valve is opened and closed in sequence by the controller. When the first valve opens, the pump will detect a drop in pressure (due to pressure release from the open valve) and will begin to operate to boost the pressure back up again. This will cause water to flow through the first (now open) solenoid valve to water the first zone. The controller closes the first valve, and immediately opens the next valve in the sequence. Once the last valve has closed, the water flow will cease, pressure will build again, and the pump will stop operating.
For ease of installation with the hotel irrigation system, the controller and solenoid valves were mounted on a black metal plate supplied with pre-drilled fixing holes, allowing it to be conveniently wall mounted. This control plate was supplied with connection to the mains power supply and was secured in a plant room located below the roof, along with the pump & tank unit. The supply pipework from the plant room to the roof surface was supplied by our client.
The hotel irrigation system watering the green roof was split into a total of 4 separate zones, the roof being watered using Permadrip-Pro dripline. Permadrip-Pro is a brown coloured dripline designed for landscape irrigation with a 16mm pipe diameter and a wall thickness of 1.2mm. The 1.6 L/h drip emitters are pressure compensating, ensuring uniform output over a wide pressure range and include a built-in anti-siphon mechanism, to prevent dirt being sucked into the drippers at the end of the irrigation cycle. These features make it ideal for use on sloping sites – such as this green roof. The emitters also have a large inlet filter and unique, continually self-cleaning design, giving excellent resistance to blockages.
For the practicality of the design, we split the green roof into two separate sections – one section being the flat part of the roof (comprising 3 zones) and the other the curved wave section (comprising 1 zone). Dripline of 0.3m dripper spacing was used. 15 runs of dripline were used for the flat section of the roof, being laid out lengthways, spaced 1m apart. 11 runs of dripline were used for the curved wave section, being laid out widthways, spaced at a wider 2.2m apart, due to the sloping nature of this part of the roof. The only exception being the 2 runs at the flat apex of the roof, which were spaced much closer, at 0.6m apart. This difference in dripline spacing was required to ensure that the whole roof was watered evenly, to counter its varying gradients. 20mm header pipe was used to run along the length of both sections (flat, and curved wave) of roof, with Pozilock compression tee and elbow fittings used to connect to each run of dripline within each of the 4 zones. Foldover stopends were used to terminate the header pipe runs and dripline runs at the end of each run. Anchorage pegs were used to secure the dripline on the substrate surface prior to installation of the vegetation blanket, ensuring that the dripline layout remained in place, to provide completely even watering.
The Result
Our project for the hotel irrigation system has resulted in a building that completely blends into its natural surroundings, with the substantial green roof attracting insects and birds and thus enhancing biodiversity. We are delighted with the result and are proud to play our part in helping to create a peaceful, natural environment to enable people to relax and de-stress.
