Frequently Asked Questions On Structural Engineering, Building Consents and more

FAQ answers on residential structural engineering, commercial engineering and industrial engineering by our experts at ProConsult in Auckland.

FAQ Residential Engineering Questions:

When do we need to engage a Structural Engineer?

Whenever you need to comply with the Building Code and the project includes non-exempt works – meaning that you need a Building Consent. However, some work, although exempt under the Building Act, will still require the services of a structural engineer.

These items are well-described in the MBIE document, which you can find here. This document explains the 5 exemptions that relate to building work for which the design is either carried out or reviewed by a chartered professional engineer, thus negating the need for Building Consent in these instances.

Structural engineers are chartered professionals who are trained to analyse factors that might exert force on a building and to calculate whether or not the structure can resist those forces (could include gravity, wind, temperature, earthquakes etc). They have training in areas concerning the structural soundness of buildings and make sure structures support and resist the loads which might be brought to bear on a building. You might hire a structural engineer when

  • altering or adding to a home: the structural engineer can ensure that you have enough support in places where you might alter loads and foundations.
  • building a new home: you need to ensure a new house plan is sound, therefore you would hire a structural engineer to maximise efficiencies of materials, compliance and soundness.
  • adding solar panels: load-bearing calculations on the existing roof, and subsequent calculations to re-design for any additional loads placed by adding solar panels on a roof.
  • buying a house or building: if there’s a structural problem – e.g., someone has done unconsented work, you can engage an engineer to report on what the actual situation is with Building Act/Council compliance

Structural damage: you might have noticed cracks in walls, doorways or foundations, due to things like subsidence of the soils, watercourse changes, excavations the neighbour might have done or earthquakes.

You might have bowing floors, standing water in basements or doors that have started sticking. A structural engineer can work out the causes, extent of damage and possible remedies.

How can I minimise costs when using a Structural Engineer?

The best way to do this is to provide a comprehensive brief, make sure you agree with the Scope of Works on the Short Form Agreement proposal, and then DON’T CHANGE IT! However, we know this can be unrealistic but if you’re aware that changes cost money, then perhaps you can better control how many are made.

Not only will you have changes in your ideas as you progress with the project, but many “cans of worms” can be opened depending on the situation. We’re happy to make quick decisions alongside your team, which you can trust us to do. A close relationship is key. We’ll keep you appraised as much as possible of anything that develops along the way which might result in extra costs.

Another good way to consolidate costs is to appoint one “lead” on the project, whether it be you, the architect, an independent project manager or the engineer. Make sure all parties know who this is, and make sure they are competent to do the job. Don’t supply things “piecemeal” – get changes done in one big lot rather than lots of small ongoing tweaks.

Tweaks might seem small to you, but they can have big implications on the architect’s or engineer’s desk, and they can even flow on to have impacts across many parts of the job that you thought were unrelated. So if you change, say, a stair design one day and a flooring layout the next, you’re likely to create more costs than if both were briefed at the same time.

BUT the biggest saving is gained when you do 90% of your designing before the professionals get started with drawing up plans.

Can we have a fixed price?

Because of the changing environment with Councils, we are reluctant to provide fixed costs. Additionally, it’s impossible with most jobs to know what will come to light after we start the design, and so we tend to give estimates only.

Estimates are usually given in relation to costs AND time needed because we simply don’t have enough control of all aspects to make promises.

For larger jobs, we can provide a fixed quote to give your project surety.

What are the Council fees for a Building Consent?

This depends on the Council in question and on your project.  For example, here is the Auckland Council online calculator.

As a rough guide, in Auckland, if you build a $1,000,000 home the council costs for something simple will be around $7,000 – $10,000 in 2022.

The engineering costs (including drawings) will be around $20,000, again for a simple design on a level site.

For a house of $2.0m to $3.0m we would assess engineering costs including drawings at $25,000 to $30,000.

Is there anything I can do at home without needing a consent from the Council?

Yes, there’s a list of items that you can do yourself or that are exempt under the Building Act. It’s definitely worth considering the scale of these items if you don’t want to incur Council requirements.

You can find the MBIE guidance list on our Resources & Links page.

Do you charge a commission on the lodgement fees that go to Council?

No. We usually collect the Council fees from you as and when they’re required, and then we pass them directly to the Council on your behalf.

You can pay directly if you wish, but in our experience, it’s better if you let us deal with Council on this and get confirmation from them that fees have been received and correctly credited.

Are you open to finding short cuts?

Our experience does allow us to streamline designs in most cases, but with compliance issues from Councils and Governments, along with the NZ engineers’ professional code of practice, short cutting is not a concept we’re comfortable with.

A previous owner completed some work that I think may not be compliant. Can you inspect it and tell me what I need to do?

Yes, we can. It’s always best to know what Council requires ahead of doing work because in some cases Council require photographic evidence of underlying structure. If this existing structure can’t be proven, then you may have to go backwards to provide the proof.

We can advise on these matters. To get post-construction compliance you may need to apply for a Certificate of Acceptance.

Does the builder I use have to be a Licensed Building Practitioner?

Yes, you usually do need an LBP if it’s Restricted Building Work. In this case, the LBP must carry out or supervise the work. The MBIE website has lots of information.

What happens if the designs you provide me with do not get Building Consent?

This does happen from time to time because various councils’ inspectors do have the power to make independent decisions.

However we stand by our work and if Council has any issues at lodgement, we take it on ourselves to satisfy their questions until the Consent is approved. This is at no cost to you.

Should I stay in my home while it’s reclad?

Our advice would be no, probably. However, it can depend on the extent of work required. It’s usually best to be able to react quickly to your building team, which would suggest that it would be good to be there. But the demolition can be rather extreme, which can be very stressful.

Can you and your family handle having no walls, and staring at white shrouds? Are you happy to have your house demolished in front of you? If you can stay sane and keep well out of the way while having your basic comforts of life greatly reduced (toileting, showering, cooking and eating, sleeping, working from home) then maybe yes particularly if only a portion of the entire dwelling is involved.

The other side of this coin is that, for the builders, it will take them longer if they have to work around you. It’s always impossible to say at the beginning of a job how much of the timber structure will be replaced for a reclad. But in order to leave, you’ll have to find temporary accommodation for 6 or 12 months – not always easy to do. Suffice to say, it’s an individual decision which may come down to emotional and financial conditions.

Is it financially worth doing a reclad?

Financially it’s usually worthwhile recladding. Emotionally, not so sure! Here are some things to consider when calculating the financial costs:

  • What did you pay for the home compared with what a replacement would cost?
  • If you sell a home with weather tightness issues, you will likely achieve only the land value.
  • Budget for Consent application is between $5,000 – $10,000
  • Cost of labour per builder per day is around $450
  • Cost of materials is rising all the time
  • Costs rise again for more complex homes
  • You can never tell, even from initial testing, how widespread the problem is.
  • If you can handle it emotionally, it will be worth doing financially – after all, a developer will do it if you don’t!

Can you get me a Code Compliance Certificate for something that was done a few years ago?

Probably yes: but we’d have lots of questions, including whether you have photographic and documentary evidence of how the work was done?

If there was no building consent to start with then you would need to apply for a Certificate of Compliance (CoC) which we can help with.

Do you do retaining walls?

Retaining walls are one of our main undertakings for residential jobs. Having seen some bad mistakes made when people take the design of retaining walls into their own hands, we can’t stress enough how this can be simple if done right, or very complex if upsetting your neighbours or failing to control subsidence is likely.

My neighbours have complained to the Council about some work I’m doing. Do I need an engineer?

If the complaint has resulted in the Council getting involved, then probably yes. We often get calls to help with changes to consented plans, drainage, retaining, fencing and boundary issues. If your site has been served with a “Notice to Fix” then it’s best to ensure you do get compliance by engaging the right team.

We provide an obligation-free advice service in situations like this.

Once I have a Building Consent, how much can I change what I do?

Not much, unless you’re happy to pay more! That’s why it’s so important to get the brief right, confirm the scope then get your plans drawn up without too many changes as you move through the process. 

However, there are some things that are exempt so in theory, can be added or removed during building work, but the work does need to be done in a compliant manner. We’re happy to talk it over.

How long will it take to get some structural calculations done on a small alteration to a house in central Auckland?

As quickly as possible! But please contact us to check what our current lead-time is: due to having several large repeat clients we can’t always start immediately. We try to give an indication, but again, due to unknowns, we do tend to give estimates.

You (and we) never know what can arise once a job starts and sometimes there are other consultants involved who make decisions that affect us. We try to do small jobs within a two-week window.

Do you get involved with the construction stage?

Only if required. We do have plenty of experience working post-consent, or through the construction stage, but this is done on a per hour cost charge.

Please be aware that at the construction stage we may do site visits without the knowledge or presence of the client to expedite the project unless the visit relates to significant changes to scope or variations. In these cases, we involve the client because the bill-payer needs the opportunity to approve or deny extra costs.

FAQ Commercial Engineering Questions:

What level of commercial work does ProConsult get involved with?

We’ve worked as part of a team on high rise and multi-unit developments. Other examples include certifying light standards as street infrastructure. Designers have brought prototypes to us for calculations: notably a proposed monorail design for New Zealand.

Along the way we’ve also worked on a variety of projects such as a container-based gym, house designs for group housing companies and converting commercial buildings for an education provider. We’ve also handled smaller commercial projects.

Stewart Hobbs, our principal engineer, is often involved with assessments of issues and writing reports on behalf of Councils, lawyers or body corporates. Whatever the scale, we can usually get involved in some way.

Can we retain your services for a large project with a tight completion date?

Yes, we can arrange to work almost exclusively on a large job; we need an opportunity to negotiate the time frames due to other on-going work. Give us a call to discuss.

Are you happy to work with other consultants and contractors?

This is our standard modus operandi. Many of the jobs we work on involve collaboration and we’re happy to either take the lead or a back seat.

Can you provide fixed prices for large jobs?

As long as the job is well-briefed and allows for cost charges if the scope of works changes, then yes, we can quote a fixed price.

FAQ Industrial Engineering Questions:

What kinds of industrial work does ProConsult get involved with?

For many years ProConsult has handled the building and hangar maintenance queries and advice for Air New Zealand. We regularly consult to various large industrial sites with regard to maintenance, alterations and safety issues.

Stewart, our principal engineer, has previous experience with dangerous, dirty and difficult site access – tanks, tunnels, towers, ovens, pipelines etc – so you can be assured that we have experience in most situations. Call us to discuss.

What does ProCosult know about industrial coatings and waterproofing systems?

This is an area we specialise in, along with concrete. Happy to discuss your requirements.

How to get Council Engineering Certification for your Structural Engineering or drafting building consent project

ProConsult has been engaged with many engineering projects throughout the country. Please contact us today to discuss your requirements.

Picture of Author: Stewart Hobbs - Principal Engineer at ProConsult

Author: Stewart Hobbs - Principal Engineer at ProConsult

Stewart is the journal editor for SESOC (Structural Engineering Society New Zealand (Inc.)

See all articles written by Stewart Hobbs

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