Creating 3D models is the fun part of Vectorworks, but contract documentation is the longest part. In most countries contract documentation accounts for 45-50% of the architectural fee. This makes it the single biggest part of the project.
You can can use the BIM principles to speed up the creation of Plans, Sections, Elevations, and you can use it to help create details, but you still need to create many details that are not generated from the 3D model.
If you get my newsletter you would have seen this sketch (all images copyright Jonathan Pickup 2016).
This sketch is from my trip to Chicago for the design summit and it was drawn on my iPad. I have been using my iPad, Apple Pencil and sketching software (Procreate).
A section is a drawing that shows a cut through an object. Many CAD programs will do this for you, but you also nee to know how to draw one of these for yourself so that you can understand the technique behind it.
Start with the plan view and protect the lines down. Next, project the lines from the elevation across to give you the heights. Add the thickness to the object.
In this view I’ve used the same technique to project the lines down from the plan, but this time of drawn a cross-section through a site. Notice how I’ve project of the lines down wherever the contours cross the section line. This is what you need to do to give you the correct site cross-section. Many CAD programs give you the ability to create a site model, and create sections where ever you need them.
Third angle projection is a common way of presenting information to others. In simple terms, a third angle projection has a plan at the top left of the page, directly below this the front elevation based on the plan above, and to the right of the front elevation a side view of the object.
In engineering drawings this is often the only drawing required by a manufacturer. For landscape and architectural projects this may not be the most suitable way to present your work. For example, your plan may be so large that you can only fit that plan on a page.
In a previous post we talked about how important it was to have line weights to to help communicate information on your drawings. This also applies to your elevations. When I was taught to draw I was taught to use different line weights on elevations to help people to read the elevations. What this means is that there should be a hierarchy of line weights that help people understand what parts of the project are projecting forward and what parts are in the background.
Line weights are extremely important. A drawing that has all of its lines with the same weight (same line thickness) is difficult to read. It’s a very common practice to use different line weights to represent different parts of your drawing. To start with, all the background information should have a thin line, and objects that require emphasis should have a thicker line.
A cold Bridge refers to a break in the insulation in the building that allows the transfer of heat. Usually this is a break in the insulation that allows the heat to escape – which can also be thought of as the cold coming into the building. This often occurs at building junctions and requires careful detailing. This also occurs with areas of different insulation values such as the studs on a wall.
Detailing Basics – Pressure Differential. Pressure Differential is the difference in pressure between the inside and outside. If the pressure difference is great, water can be drawn up vertical faces, through gaps, and into the building. The solution is to have air seals at all joints.
Kinetic energy is where the water is moving. Generally, this is where the water is being blown by strong winds. I have used the roof example, which is common where I live. The wind often blows water up the roof slope, and under flashings. The flashings will stop a lot of the water, but without a stop end on the roofing, the water can enter the building.
The surface tension in water makes it stick to the surface of objects. A classic situation is where the water runs under a soffit or under a stone or concrete windowsill, the water will run into the building along the horizontal surface. The situation is very easy to fix, all you need is a break in the horizontal surface. A vertical change in direction or a sawcut in the concrete or stone sill will cause the water to drip off the object. This is often referred to as a drip edge.
Capillary action is where the surface tension of the water can pull the water into small gaps. Any gaps in your building that are less than 5mm (1/4″) could allow water into your building. Capillary action is extremely powerful, and can even overcome gravity, allowing water to creep up a detail and into your building. The good news is that it’s extremely easy to solve. All you need is a gap that is wider than 5 mm (1/4″). If you look at good detailing you will notice that there are often gaps at the bottom of flashings that will prevent water from creeping up the detail.
One of the big problems with keeping water out is gravity. Water tends to fall down the building or is pulled down the building by gravity. While this is a big problem it’s also one of the easiest to solve all you need to do is to deflect the water away from the building.
When you draw details to communicate to others how the project is built, you need to show how the materials join together how their fixed and how you intend to keep the water out. It might not seem a big issue, but keeping out water is one of the fundamental problems in detailing. Water can cause structural and health problems.
The five most common ways for water to enter the building are:
- capillary action
- surface tension
- kinetic energy
- pressure differential
We need to draw details to communicate to others how the project is built, how the materials join, how they are fixed together, and how we keep the water out. Water may not seem much of a problem, but if you have lived in a country where they have had leaky buildings, you will know that water is a big issue. Water can cause health and safety issues and it can also cause buildings to fail through rot, corrosion, and through ice. Each Wednesday we will be looking at drawing and detailing topics. We will be covering detailing principles, drawing concepts, where you need details, etc.