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Suite 4.02, 17 Macquarie Street

Parramatta NSW 2150






(02) 4721 1955



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Inhouse Consulting Engineers have proudly serviced Sydney for over 30 years

About Your Consulting Engineers in Western Sydney

Our Heritage


1988 - Founding and Early Years


The practice first started trading in Penrith, western Sydney as Roger E Dohnt & Associates in July 1988. Prior to this Roger had served most recently as Principal Structural Engineer at another well-known local development consultancy - Morgan Talbot Associates Surveyors and Engineers and the NSW Department of Housing before this. Roger saw the potential for a specialized structural engineering firm servicing the growing Penrith Valley and Blue Mountains region and the company soon began its journey by providing high-quality structural engineering services to local clients including building and civil engineering firms. 


1990s - Growth and Expansion


The 1990s marked a period of great economic development in Penrith which continued to serve as a regional centre for business and commerce. The demand for housing in Penrith also increased, leading to residential development projects in both established suburbs and new housing estates. With this, the firm experienced significant growth as its reputation for excellence in structural engineering continued to grow.


The company expanded its client base, taking on various projects, from residential developments to commercial and industrial structures. In 1994, the company began trading as Inhouse Consulting Engineers reflecting its role as a trusted structural engineering partner relied upon by other engineering firms and land developers to provide specialist structural engineering services.


2000s - Consolidation and Prosperity


Inhouse Consulting Engineers continued to broaden is client based and services in a decade initially marked by strong economic conditions following the Sydney 2000 Olympic Games and increased ties with China and the mining boom. The Global Economic Crisis which caused extreme stress in global financial markets and banking systems between mid-2007 and early 2009 would have little impact on the continued prosperity experienced by the business which had by now firmly established itself a leading structural and remedial engineering firm.


2010s - A Second Wave of Growth


In 2010, following a period of exceptional growth, the practice relocated to a larger shopfront office on the Great Western Highway at Kingswood in western Sydney as additional engineers and a full-time structural drafter joined the quickly expanding team.


To accommodate the rapidly expanding team and workload, Roger hired his son - Daniel to assume day-to-day management of the business and additional administrative staff were also employed.


In 2017, in the company invested in its first fleet vehicles, two Land Rover Discovery 4x4s to assist in covering an increasing client footprint which now includes structural certifications of some of Sydney's largest residential land release areas.


The end of the decade was defined by the 2019 bushfires, a national disaster which Inhouse Consulting Engineers would work with the insurance industry to undertake field inspections of damaged properties to assist with the claims process and help families get back on their feet.


2020s - Challenges and Renewal


In the face of new challenges, such as Australian Bushfires, the COVID-19 pandemic and 2021 - 2022 floods and Inhouse Consulting Engineers displayed resilience and adaptability. The company temporarily shifted to remote work during imposed lockdowns and continued to support its clients now coping with the flooding disaster and again working closely with the insurance industry to undertake hundreds of structural assessments of people's homes.


Owing to its exceptional growth and resilience over 30 years, Inhouse Consulting Engineers welcomed new owners in July 2022 joining part of a successful planning and land development consultancy firm. 


The firm relocated to a new corporate Head Office in Parramatta in November 2022 in order to accommodate an expanded team of civil and structural engineers and town planners and better service our clientele right across the Sydney Metropolitan area and beyond.  


Present and Future


Today, Inhouse Consulting Engineers continues to provide structural engineering services across a variety of sectors, contributing to the growth and development of the Sydney region and now services the Newcastle and Hunter, Central Coast, Illawarra and Southern Highlands regions.

Our mission is to provide expert structural engineering services while adapting to the evolving needs of the industry which has been a driving force of our success.


As we look toward the future, Inhouse Consulting Engineers are well-positioned to continue to play a vital role in shaping the landscape of Sydney and beyond with our continued dedication to engineering and development excellence. This will be achieved through embedding technological advancements in the field of structural engineering, incorporating state-of-the-art software and tools that enhance our capabilities. 


As environmental sustainability became a paramount concern in the construction industry, Inhouse Consulting Engineers embraced green engineering practices. The company is committed to sustainability and has implemented eco-friendly strategies including replacing its vehicle fleet with new, smaller and more economical vehicles and using only E10 fuel, going paperless and switching to an all-digital filing system.


Inhouse Consulting Engineers is currently undertaking the following ISO Certifications:

  • ISO 9001 – Quality Management Systems
  • ISO 45001 – Occupational Health and Safety Systems
  • ISO 14001 – Environmental Management Systems

We expect to complete certification in January 2024.

Our Team

Currently, the firm employs one full-time Principal Structural Engineer, two full-time Senior Structural Engineers, one full time Structural Engineer, one full-time Trainee Structural Engineer and one full time draftsperson. Additional contact engineering and drafting staff with relevant experience and skills can be sourced at relatively short notice to suit fluctuations in the workload.


Name and Qualifications

Principal Structural Engineer

Lithesh Prasad

BE Civil (Hons), MIE Aust, CPEng, NER

Senior Structural Engineer

Nathan Haddad

BE Civil (Hons 1), BPM, MIEAust, CPEng, NER

Structural Engineer

George Agapiadis

BE Civil, MIEAust

Trainee Structural Engineer

Domenic Haddad

BE Civil (Candidate)

Structural Drafter

Trung Ngyuyen


We are ably supported by the following executive team:
  • Wesley Folitarik – Managing Director
  • Yan Folitarik – Financial Controller
  • Jasmine French – Office Manager
Our Office
Inhouse Consulting Engineers operates out of a modern corporate office in the heart of the Parramatta CBD. 


We use latest technology including structural design software, RAPT, DRAINS, TEDDS, S-Frame & P-Frame, Space Gass and Bluebeam. All drafting is carried out using AutoCad software. 


We have a fleet of modern vehicles with four‑wheel drive capability to enable access to the toughest sites. 


We have tools for geotechnical soil sampling and testing for foundations including hand auger and hand and dynamic cone penetrometer for DCP tests. Soil samples are tested off site by NATA registered soil laboratories as required.


We are able to inspect difficult structures with our DJI Mini Pro 4 Drone and our engineers have all undertaken working at heights training. We partner with rescue and recovery consultants for inspections of confined or high risk structures to ensure employee safety.


We also have a laser levelling station and accessories that we primarily use for measuring deflections in structural elements.
Our Clients
The practice has successfully traded for over 35 years and is proud to note the following distinguished clients amongst its broad base of architects, builders, property developers and government agencies:
  • Incoll Management Pty Ltd                  
  • Landcom                                     
  • Western Sydney University
  • Penrith City Council                    
  • Australand Holdings                             
  • Delphin Lend Lease
  • Norwest Land
  • Blue Mountains City Council
  • Redbank Communities
  • Lend Lease
  • Western Earthmoving
  • Taylor Construction
  • Randwick City Council
  • JMD Design
  • Raine & Horne
  • CGU Insurance
  • Enspire
  • Penrith Lakes Development Corporation
  • Hills Shire Council
  • A.R.F. Industries
  • Housing NSW                                  
  • J. Wyndham Prince                             
  • Department of Defence                                  
  • Anglican Church of Australia
  • Clouston Associates
  • Jones Lang LeSalle
  • Cumberland Council
  • TRN Group
  • Department of Planning, Infrastructure & Environment    
  • BCM Property Group
  • NRMA Insurance
  • Allianz Insurance
  • White Wolf Constructions