The importance of Landscape Architecture as an integral part of building & development projects:
Landscape architecture is not an isolated discipline and needs to be considered as an integral aspect for the success of any building project. As an architect and landscape architect, I have encountered many projects which would have benefited with the services of a landscape architect at the design stages.
The landscape surrounding a building is a grossly undervalued space. Well placed trees and associated landscaping can accentuate the beauty of any building. The landscape links a building to its surroundings, and may improve the appearance and amenity of the building as a whole.
Landscaping is the first item to be deleted from a project if the tender is high. The impact of a completed building is immediate. A completed landscape may take 2-5 years for real impact, so it might be difficult to convince a client to allocate funds for landscaping.
This article describes some of my experiences and thoughts. It is by no means comprehensive, but is intended to outline some issues which should be considered.
Masterplanning & Site Analysis.
A project brief outlining the client’s requirements and helps to determine the relationships of indoor areas to outdoor areas. This is a good is a good starting point, and input during early stages can help to identify potential issues.
- A site investigation will identify features that can be retained. Mature trees are often disregarded, and removed by developers.
- The topography will determine the need for terracing, retaining walls, drainage and water features as will the location and depth of existing services. Understanding the soil type, microclimate, and views are also considerations.
- Buildings generate shade. Exploit that shade to best effect where appropriate. Locate trees for best effect to shade, screen, frame, or direct a view. There are economic benefits to heating & cooling a building with well placed trees pergolas as part of the landscape.
- Safety issues need to be considered: DDA complaint circulation & spaces, tripping hazards, careful ramping & steps all in accordance with regulations; steps & risers need to be appropriately sized for outdoors.
The various authorities have strict requirements regarding utilities: the location of fire services, gas, water, and electricity meters needs to be considered early, to allow for their siting so that they do not dominate. The location & depth of existing drains, sewers and easements will have an impact on the final landscape plan. This is critical on sloping sites where terracing and retaining walls are needed.
Structural and civil engineers need to be consulted to ensure the structural integrity of any retaining wall, so that drainage pits and sewers are not compromised by the design and location of proposed features. Dial before you Dig is a good starting point during design stages to ascertain details of utilities.
Ultimately the location of any proposed trees is influenced by the depth & location of stormwater and sewerage drains. Where necessary, root barriers can be located to minimise any potential damage to drains.
Drainage, Stormwater Management and WSUD
In the past, stormwater drains were designed to redirect runoff into stormwater drains to prevent flooding of the site. Rainfall is lost to the site and disappears down the drain to the bay.
Recent developments by Melbourne Water introduced rain gardens, bio retention swales, constructed wetlands and other water saving measures to better treat this runoff in housing developments. Melbourne Water has produced publications that describe such measures, and many councils have their own versions that provide information to gain some understanding of what is required. Options can be discussed at the planning stages in conjunction with consultant engineers to achieve a good solution:
- WSUD elements should be suggested at an early stage for inclusion where appropriate. i.e. bio-retention pits and swales, & kerbs that permit runoff to landscaped areas.
- Raingardens in residential projects need to be located so as not to affect the footings; a specialised plumber or engineer should be consulted in the design of WSUD elements.
- Drainage pits can be located to suit a pattern in a paving layout, or be located in a garden area using a bio-retention system.
An irrigation system was deleted from an educational project at the construction stage. Some years afterwards, during later stages of the same school development, and a different project team, there was criticism that irrigation had not been included. The landscaping in those early stages has suffered as a result of this, and is quite barren, with little shade from the few trees that were planted. The irrigation was then retrofitted at a much greater cost.
During later stages of this project, I was involved in meetings with all consultants available for discussion. This was invaluable for everyone involved, and it was possible to suggest and negotiate the location of pipes and drainage pits to suit the landscape, determine appropriate levels to avoid flooding, and to suggest where trees were to be placed. Likewise the landscape was amended to suit other constraints brought up in these meetings. This was beneficial to all involved, and potential problems were addressed early in the design process.
One of the first things a builder does is to scrape and remove topsoil from the site. This soil should be stockpiled on site for later re-use and mixed with any imported topsoil. Soil preparation is often not adequately monitored on site with the result that planting establishment is compromised.
As a landscape architect, my involvement is often limited to design and documentation to tender stage, and I am not engaged during the construction process. Therefore as an architect on site it is wise to carefully monitor this aspect and ensure that adequate soil preparation occurs. A qualified landscaper should, in theory, know the typical requirements for successful planting establishment and be able to follow any specific requirements of the specification. At times, the builder will undertake the planting, with inadequate soil preparation.
During the construction process, the coming and going of vehicles will compact the soil. This may result in an almost concrete-like soil profile and, unless such areas of compaction are treated to break up the soil, any areas of planting are likely to fail.
Protection of Root Zones of Trees
Any building materials, soil or rubble placed under the root zone of a tree will have a detrimental impact on the future health of the tree. Over the following year or so, the tree canopy may show signs of stress, and in time the tree is likely to die. The planning permit may set out details of tree protection, and at times these are not adequately followed. As an architect, it is important to have an understanding of the impact of the construction process on existing trees and to monitor this on site.
Landscape Plans for Housing Developments
I have undertaken simple landscape plans to satisfy planning permit requirements for small scale housing developments. I have had a client say to me, “Just put in anything – and I will pull it out and plant what I like afterwards.” Councils may require a certain percentage of native plants which the client perceives as unattractive. The careful selection of planting, exotic, native, indigenous or otherwise, does make a difference, and plants can be selected that the client will appreciate.
Ongoing maintenance of the landscape is an importance consideration and has long term benefits. The planting establishment period may be 13 weeks, or 12 months for larger projects. Regular management of the landscape is critical to the ongoing health and vitality of the plantings. A landscape maintenance plan can be provided, and is an excellent tool for the client to ensure that ongoing maintenance occurs.
Working with a Landscape Architect:
A landscape architect offers a different but invaluable perspective on a project and can advise on a number of site issues which other disciplines may not consider. This is not limited to plant selection, but in conjunction with other consultants may identify and solve potential issues during the design stages.
I have encountered architects who do not look beyond the building to be designed. Site plans have been e-mailed, without floor plans or elevations. The association between internal and external spaces is an important starting point for any landscape design.
To save costs, it has been suggested to me that a site visit is not necessary. Understanding the site in its context is an important element in the design of any landscape.
- A minimum landscape budget needs to be committed early on.
- Engaging a landscape architect during the early stages of a project has many benefits, and may save costs in the long term.
- This assists to Identify and solve potential issues that may arise during construction and may avoid retro-fitting during later stages.
- A landscape masterplan will identify areas of hard and soft landscaping, links, circulation and suggest future staging of works.
- Planting areas, and in particular narrow planting strips need to be sufficient is size to support planting to suit the purpose. Inadequate space will inhibit planting establishment.