Carnlough HousingDevelopment Portfolio Report Ben108- Construction Technology 1Keith Hall B00749683 Contents Contents. 1Introduction.
2Foundations. 3External Fabric. 4Internal Fabric. 5Roof 5Cold water intake. 8Heating systems. 11Hot water system.
. 11Summary. 11References. 11Appendices. 11 IntroductionThis report is based upon the proposed construction of five domesticdwellings within the coastal village of Carnlough in North East Antrim.
Throughout this report the aim is to discuss the main elements that comprisethe construction of domestic dwellings and to select the appropriate methodthat should be used in the site at Carnlough. Carnlough is on the causeway coastal scenic route and is part of the Midand East Antrim district. It has a picturesque harbour built to supply andtransport the nearby quarries, it has since been renovated to be used byfishing and pleasure boats. This creates an appeal for the village in tourismand habitation.Domestic dwellings are in demand in this village. “A new build scheme wason site in Carnlough to provide seven dwellings which will help address ruralhousing need in the area.
” NIHE (2014)The proposed site as shown in the appendix is in the north of the town. It is nextto a recently built housing development and is within walking distances to thenearby shops primary schools as well as a short drive to the nearby secondaryschool, Larne is the nearest town 13 miles away. Appraisal-Health and safety is a priority when it comes to any project regardless ofsize. HSENI regulations ensure that risk assessments are carried out on everybuilding site to reduce the likelihood injury to workers or to members of thepublic. The site is 1.3 hectares and will have 5 plotted dwellings.
The site shouldbe a restricted site for health and safety reasons. Children from the nearbydevelopment could be attracted to the site hence why appropriate fencing andsignage should restrict unauthorised access. The site will be accessible to deliveries of materials and is ample size tostore materials during the build. Powerlines run across part of the site andthis must be taken into consideration as high sided vehicles may haverestricted movements within the site.
The site is built on a slope and as a result there will be a section offilled ground within which four plots will be built on. This will be taken intoconsideration through the construction of the foundations section. This will be part of remedial work requiredby the site.
With regards to the style of the dwellings they could potentially be builtto match the style of the area. The surrounding homes are of single storeyconstruction with 4 bedrooms, both terraced and detached with brick and whitewashfinish. Homes in the area at the time of writing this report cost £95,000 inthe adjacent development for a similar dwelling. (Daniel Mcalister & SonEstate Agent, 2017)A benefit for the site is that due to its proximity to housing there is arelative solution to services requirements. Fitting plumbing and heating to thesite may come at a reduced cost as a result. Finally, this site is in a well accessible area, can be made safe and islocated near homes at reasonable prices.
The site could be easily fitted withwater and heating however further research is needed. There is also scope forbuilding detached or semi-detached housing with the addition of a garage whichwould add to the potential value. FoundationsFor this report the analysis will focus on one plot within the proposedsite. The plot in focus is plot two. The plot in question lies atop filledground and as a result will require a suitable foundation for the type of fill.Foundations are the subfloor support of a building. They transfer the loadsof the building, both static and dynamic, to the ground. Foundations should bedesigned to support all expected loads and in some parts of the world bedesigned to withstand natural disaster such as earthquakes.
When designing foundations there are three principles to consider, theexpected loads, the soil type and bearing capacity and finally the siterestrictions. For this site the soil typical of the area is boulder clay. This is acohesive soil type that can support between 400 and 800 kN/m2 of load and wouldbe suitable for building domestic homes on with strip foundations.
When fill is factored in the site may have some restrictions. Simpson andPurdy (1984) State ‘Properly graded and compacted fill can be stable with onlymoderate compressibility and good load bearing capacity. Wide or deep stripscan be used with no additional costs… in comparison poor natural compactionfills which have been badly placed can mean normal strip would be inadvisable…’For this report research of the site shows that the gradient of the slopeon this site is minimal and the fill may not be much deeper than 2000mm.Assuming the fill has been properly graded then I would recommend a stripfoundation for this site which wouldn’t need to be at a depth of more than500mm.
This relies on the fill being well compacted and firm. In accordancewith the technical booklet D of building regulations (2012) the trench shouldbe no less than 400mm wide to support a load not greater than 40kN/m. For the flooring I would suggest a t-beam and block raised floor. Wheninsulated and dampproofed this should prevent any water penetration from thesoil and any cold bridging. (see appendix) External FabricWalls-The external fabric of a building is designed to resist wind load, preventwater perforation, reduce the amount of heat loss, allow for daylight andgrants access to the building.
Part of the external fabric provides thedwelling structural support. For modern dwellings there are 3 main types of wall, porous, rain screenand cavity wall. For the Carnlough development the most suitable option is thecavity wall. The area is on the North Antrim coast and there are moderateamounts of rainfall all year round. A cavity wall’s purpose is to allow anywater that penetrates the masonry of the outer leaf to drain through a gapbetween the outer and inner leaf. The water should not penetrate the inner leafas a gravity allows water to leave through holes in the outer leaf masonry atthe base of the wall.
The outer leaf for the development could be completedwith brick or blocks and to keep with the style of house in the area shouldhave a whitewashed finish. In keeping with the building regulations, the cavitywalls outer and inner leaf shall both be tied to one another using brick ties.The reason for this is to allow for structural stability and allows for somemovement in high winds which are also prevalent in the North coast. Where the outer leaf can be comprised of brickwork or blockwork the innerleaf can be made from timber frame or SIPs.
“SIPs panels consist of aninsulating core bonded between two structural facings. Built off-site, thepanels are very fast to erect on site and achieve good U values and excellentairtightness.” Snell (2017) SIPs board construction may be slightly moreexpensive than timber or blockwork but they can significantly reduce build timeand other associated costs. For this project SIPs could potentially be anaffordable option. The closest merchant for these fitted panels are near Belfast.This would mean materials could be transported to site within 2 hours based onthe location which is easily accessible via coastal route. The Resistantcompany boards may be safer than timber frame based on their ‘non-combustible’design.
The base board 10 design is…
weather and mould resistant, breathableand vapour permeable, robust, and high strength, non-combustible sheathing andhas pre-insulated panels. Resistant (2017) Internal FabricIn terms of internal factors, we include the walls, upperfloors, stairs, and doors. Each are set out in the building regulationsbooklets and should have sufficient fire ratings in modern domestic buildings. Walls- there are 3 types partition, party, and compartment. Asthis is a detached house there is no need for a part wall as there are noneighbouring homes. As for the partition walls there are a few options, timberstud or metallic stud.
The metallic stud walls are generally easier to fit. Forthis development however, the timber stud frame would me more appropriate inkeeping the aesthetics pleasing in the dwelling. Resistant also supplypartition wall fittings which can be used much like the external leaf outlinedabove. A description is outlined in the appendix as shown. This insulation meets fireresistance in compliance with British standards and building regulations forpartition walls. Upper floors- should the house have been builtwith internal blockwork rather than the resistant boards selected then T-beamand blocks would be appropriate. In the case of the development timber joistscan be fitted to the resistant board and timber stud design as laid out by theresistant company. Shown in Appendixin compliance with building regulations.
Stairs/doors- there are numerous designs in whichstairs can be constructed. For this development a standard method would be anacceptable choice. Millar wood crafts provide traditional staircase joinery. Theirlocation in Randalstown is ideal and within reasonable distance to the site andwould be an advisable choice of joinery specialists to fit the stairs in thisdevelopment. Some of their work is shown in the appendix. Doors for this property should have a hardwood core toprovide a good fire rating. They can come in many different designs and can beprovided by the Millar wood crafts. This could also come cheaper as part of adeal.
RoofThe roof has a variety of purposes in domestic buildingconstruction including protection from different elements such as rain snow andwind, parts of the roof provide protection to the structure’s interior andexterior. Design – Fig 1, example of a dormer roof, Wessex building products (2017) Roofs can be of flat or pitched design. For this area aflat roof would be out of fashion, so a pitched roof design would be advised.
The roof could if desired be made as a habitable area. As a result, the wholeroof would need to be insulated. With a continuous gap of 50mm gap outside theinsulation to prevent moisture and condensation build up as recommended byBritish Standards.
For this project a dormer roof could be a reasonable option.Should the loft be used as a habitable room then the dormer comes with a windowextension as shown in fig.1. As for the garagethe roof can be of lean-to design for aesthetic purposes.
Roof options-There are two ways to construct a roof, cut or trussed. Acut roof is designed, cut, and built on site. The advantages of this type ofroof are mainly to do with site restrictions.
If the site is in a built-up areaor has poor road access, then the materials can be easily stored on site andthen built to a pre-designed specification. As for disadvantages this method can be more expensive than trusseddesign. Cut roofs are more time consuming and generally have wastage ofmaterials which adds to costs. For trussed roofing this can be a more cost and timeeffective investment. These roofs are factory built and can be tailored to meetthe needs or specifications provided by clients. The roof then can be assembledon site without any wastage of materials. The implications for this type ofconstruction are that the site needs to have good road access and enough spaceto safely assemble the roof.Site-For the Carnlough plot there is scope for using thetrussed method.
Just as there is easy access for the SIPs there is amanufacturer of trussed roofs in Carrickfergus, called Trussed Solutions. As aresult, it would be recommended for time and to keep expenses low that atrussed roof would be suitable for this. Precautions would also need to betaken to ensure health and safety around the overhead powerlines. Cold water intakeCold water is a necessity in all households.
Estimates vary, but eachperson uses on average around 150 litres of water per day. Most of this wateris used in showering, followed by washing machine and dishwasher use, andfinally in drinking purposes. Fig 2 site plan- sewers and mains based on assumptions (red ) InNorthern Ireland cold water supplies come in the form of loughs, reservoirs,and wells. Northern Ireland water provide and own the rights to the pipes up tothe border of the house. Here the service pipe becomes ownership of thehouseholder.
As shown in fig.2 the sewer line and water mains would run alongthe road as standard. A connection could be made through NI water. Household provision-Within domestic households there are two methods for cold water supply,direct and indirect. Direct method- throughthis method the mains water supplies all the household’s water outlets. Thismeans that drinking quality water can be obtained from every outlet. A cold-waterstorage tank may be needed required based on heating system but isn’tnecessary.
Using a direct method, the cost of pipework is reduced, safe drinking watercan be obtained throughout the household, and only a small tank may be requiredif at all. Fig 3, example of a direct method setup, DIY Doctor home improvement hub (2017) Forthis system problems can arise if the mains supply is cut off. As a result, ifthere is no tank then the home will be left with no reserve. There is apotential for back siphonage in this system.
Lastly if there is more than oneoutlet being used at a time then the pressure can drop thus reducing the speedat which flows from each outlet. See fig.3 for a basic set up for directmethod.
Indirect method- In this system the water bypasses all outlets in the household except for apipe that runs directly to the kitchen sink. The water connects to a storagetank. From this tank there is a distribution pipe that takes water to theremaining outlets.
The water in this case is not of drinking quality. It ishowever less economic than the direct method in terms of pipework as more thanone pipe feed the outlets. As a result of using a storage tank and not alloutlets being connected directly to the mains then the pressure is less likelyto drop in this case.
Should the mains be cut off then the benefit in this systemis that there is a cold-water tank that will last for some time before themains flow returns. The indirect method has been outlined in fig 4. Fig 4, example of an indirect method setup, DIY Doctor home improvement hub (2017) For this plot it may be asound investment by selecting a direct system. This along side a small storagetank would be beneficial, hence providing some water retention in the case ofwater outage. To prevent back siphonage each of the outlets should be fittedwith an air gap to allow for an overflow. Heating systemsThermal comfort is a necessity in any household. Thermalcomfort is perceived as being comfortable under surrounding environmentalconditions.
In Northern Ireland heating is a priority especially throughout wintermonths. This plot will require sufficient heating elements to provide suitableconditions all throughout the year.Similarly, as with the cold-water system there are twomethods to household heating, direct and indirect. Direct- This comes in the form of four categories of heating;solid, liquid, gas and electric. Solid- fuels include the traditional wood or coal burning fireand the modernised multifuel stove. Open fires can heat the whole property andgenerally adds to the aesthetics however can be highly inefficient, and it createsexcessive air changes, causing draughtsand heat loss.
The modern and increasingly popularmultifuel stove can be up to 50% more efficient than a fireplace. It reducesthe amount of dust and reduces the likelihood off heat loss. Oil/liquid- is similar to the traditional solidfuel method. Although it can be more efficient it can be a costly venture. Itmust constantly be refilled as a storage tank is required on the property. Thetank must be leased in most cases by the householder and fees for oil. Fig 5, Burley Ambience Stove – Flueless Gas Stove by Onestop fires.
(2017) Gas- there are a number of systems for gas provision. In place of a fire thereare decorative fuel effect fires and inset live fuel effects. These bothprovide an aesthetic appeal to gas as a fuel. Radiant convecters and flueless fires can be built intowalls. Flueless fires produce virtually no carbon monoxide. The gases are alsocleaned by a catalytic converter built into the system making it significantlysafer than solid or liquid fuels.
Carbon monoxide poisoning has been a majorproblem with gas fuel. By using a flueless fire the liklihood of carbonmonoxide production is reduced. Electric- the final method for direct methodof heating this comes in the form of direct and indirect radiators or heaters.This can be a costly heating method however can be easier to fit in householdsin comparison to the other fuel types. Indirect methodThis comes simply in the form of a central heatingsystem. These come in three types as: wet systems, warm air and storage heaters,as provided by Uswitch (2017). Of the 3 warm air systems are mostly used incommercial buildings and may not be recommended for the site in Carnlough. Wet systems’With a ‘wet system’ hot water circulates through asystem of pipes that connect to the radiators throughout a house.
At the centreof the system, a boiler burns a fuel – or sometimes there is a ‘heat exchanger’and this heats the water that feeds the network of pipes to supply theradiators which heat the rooms via convection.’ Uswitch (2017)Wet systems that are heated by gas have a water basedmedium within a boiler. When the water is heated it can be transported to theradiators via gravity or being pumped.There are two designs in terms of piping, one and twopipe designs.
The one pipe system is a cheap method for installation however itcosts more to run as eachsuccessive radiator receives water that has been mixed with cooled water fromprevious radiator.Thealternative to this is a two pipe method. This way the water leaving eachsuccessive radiator doesn’t mix and the radiators will all be at the sameconstant boiler temperature. The pressure in this system is maintained at ahigh level so more radiators if require can be added. Storage Heaters- contains bricks capable of storinglarge amounts of heat. ‘These are heated overnight using the off-peakelectricity on Economy 7 and, on Economy 10 tariffs, during two shorter periodsduring the day.’ This heat is then released the following day slowly. This is amore efficient use of electricity than in the direct method.
The heaters can betimed to save money especially in warmer months of the year when the heatersmay not be needed much or at all. The one and two pipe systems are sketched outin the appendix. Site- for the Carnlough development it would be appropriate toselect the more efficient indirect heating method. Uswitch (2017) In terms ofcons, it is worth noting that electric central heating is often more expensiveas electricity unit prices are up to four times costlier than gas prices. Ontop of this, electric central heating storage heaters do not provide instantcontrol.
This means you will have to plan your heating needs ahead as switchingthe heating on at night means it will heat up for the next morning. It is forthis reason that gas would be best for the site. In the long term the gascentral heating will be more cost effective. The site should also incorporate atwo-pipe system to ensure the best all round quality, pressure, and warmtharound the property. Hot water systemTypes- we use the hot waterin taps baths and showers as examples. Again, there are two types direct andindirect. The difference between the two systems is in the direct system watermixes with water that is used for heating the house, meanwhile in the indirectsystem the water is heater through a heat exchanger or coil and never mixeswith the heating water. Within the direct system this can lead to furring ofthe in the boiler and pipework, if it is copper.
The indirect system can be described as amore efficient method although it does require a storage tank. For this reason,it would be beneficial to select an indirect method for the site. This is dueto the previous recommendation for the indirect cold-water system whereby astorage tank will also be included. The main problem to this method is aslightly more expensive running and maintenance cost however the benefits ofdecreased furring and increased efficiency outweigh this.
In this system animmersion heater may be a good addition as it provides instantaneous heat whenturned on. This can be effective for when there is a need for hot waterwhenever the heater hasn’t been on ie, during summer months. The two systemsare shown in the appendix Solar panelwater heating- on a final note for water heating there is scope for usingsolar panels in this development.
This puts a sustainable outlook on theproject. To save on using an immersion heater during the summer months solarenergy could heat up water without using fuel. This comes in the form of flatplate collectors or evacuated tubing. The flat plate collector is up to 15%cheaper to produce than evacuated tubing however the latter is more effectiveat producing hot water. I would recommend that the development includeevacuated tubing for efficiency especially in a cold climate country.
SummaryTo conclude this development is in a desirable area.Carnlough has been subject to a housing deficit and as a result thisdevelopment is much needed. Within following thebuilding regulations this project can be constructed to meet safetyrequirements and provide adequate housing in the Carnlough area. The homes inthe area have been considered and the designs of the development have beenselected accordingly to maintain similarity to the surrounding developments. Services such as; electricity, heating, and waterprovision can be easily connected and fitted due to the surrounding provisions.Finally, the research in this project are guides that have been made based on assumptionsabout the site in question and further research would be needed such as soil conditionsand water pipe locations. ReferencesWeb PagesNIHE, Larne District Housing plan 2014.
Online. 19October 2017. Available from: https://www.nihe.gov.uk/larne_district_housing_plan_2014.pdf Daniel mcalister & son estate agent. 2017.
19 CroftAvenue, Carnlough, Ballymena, Antrim, BT44 0EN. Online. 22October 2017.
Available from: https://www.propertynews.com/Property/Ballymena/DMS670370/19-Croft-Avenue/ Snell, D. 2017. Comparing wall system costs. Online. 22November 2017.
Available from: https://www.homebuilding.co.uk/comparing-wall-system-costs/ Resistant. 2017.
Base board 10. Online. 23November 2017. Available from: http://www.resistant.
co.uk/base-board-10/ Uswitch. 2017. Central heating systems: what kinds are there available?.Online.
11 December 2017. Available from: https://www.uswitch.com/boilers/guides/central-heating-systems/ Pawlings. 2017. Internal stud walls. Online. 12 December 2017.
Available from: http://www.pawlings.com/insulation/wall-insulation/internal-stud-walls/ BooksGalloway, T (2004).Solar House A Guide for the Solar Designer. Oxford: Architectural Press. Simpson, B.
J , M.T (1984). Housing on Sloping Sites a Design Guide. New York:Construction Press. Chilvers, P, Hill, D & Owen, J (2007). Before you build- A step-by-step guide toextensions and renovations.
London: RIBA. Appendices